diff --git a/Controller/Checkout/RestoreCart.php b/Controller/Checkout/RestoreCart.php
index 8f3655a..d3875ff 100644
--- a/Controller/Checkout/RestoreCart.php
+++ b/Controller/Checkout/RestoreCart.php
@@ -11,7 +11,6 @@
  */
 namespace PostFinanceCheckout\Payment\Controller\Checkout;
 
-use Magento\Checkout\Model\Session as CheckoutSession;
 use Magento\Framework\DataObject;
 use Magento\Framework\App\Action\Context;
 
@@ -21,27 +20,18 @@
 class RestoreCart extends \PostFinanceCheckout\Payment\Controller\Checkout
 {
 
-    /**
-     *
-     * @var CheckoutSession
-     */
-    private $checkoutSession;
-
-    /**
-     *
-     * @param Context $context
-     * @param CheckoutSession $checkoutSession
-     */
-    public function __construct(Context $context, CheckoutSession $checkoutSession)
-    {
-        parent::__construct($context);
-        $this->checkoutSession = $checkoutSession;
-    }
-
     public function execute()
     {
-        $this->checkoutSession->restoreQuote();
-
+        try {
+            // Triggers event to validate and restore quote.
+            $this->_eventManager->dispatch('postfinancecheckout_validate_and_restore_quote');
+        } catch (\Exception $e) {
+            // If an error occurs, we display a generic message and redirect to the cart.
+            $this->messageManager->addErrorMessage(__('An error occurred while restoring your cart.'));
+            return $this->_redirect('checkout/cart');
+        }
+
+        // Redirects to the cart or to the path determined by the redirection.
         return $this->_redirect($this->getFailureRedirectionPath());
     }
 
diff --git a/Controller/Transaction/Success.php b/Controller/Transaction/Success.php
index c11f9af..882e9af 100644
--- a/Controller/Transaction/Success.php
+++ b/Controller/Transaction/Success.php
@@ -61,6 +61,14 @@ public function execute()
                     'However, the payment was successful. Please contact us.'));
             return $this->_redirect('checkout/cart');
         }
+        
+        // Deactivate quote after successful payment.
+        $quote = $this->checkoutSession->getQuote();
+        if ($quote && $quote->getId()) {
+            $quote->setIsActive(false);
+			$quote->removeAllItems();
+			$quote->save();
+        }
 
         $this->checkoutSession->setLastOrderId($order->getId())
             ->setLastRealOrderId($order->getIncrementId())
diff --git a/Model/Config/Source/IntegrationMethod.php b/Model/Config/Source/IntegrationMethod.php
index 0b54c61..ca5cd86 100644
--- a/Model/Config/Source/IntegrationMethod.php
+++ b/Model/Config/Source/IntegrationMethod.php
@@ -19,7 +19,7 @@ class IntegrationMethod implements \Magento\Framework\Option\ArrayInterface
 
     const IFRAME = 'iframe';
     const LIGHTBOX = 'lightbox';
-	const PAYMENT_PAGE = 'paymentpage';
+    const PAYMENT_PAGE = 'payment_page';
 
     public function toOptionArray()
     {
@@ -31,7 +31,11 @@ public function toOptionArray()
             [
                 'value' => self::LIGHTBOX,
                 'label' => \__('Lightbox')
-			]
+            ],
+            [
+                'value' => self::PAYMENT_PAGE,
+                'label' => \__('Payment Page')
+            ]
         ];
     }
 }
\ No newline at end of file
diff --git a/Model/Resolver/UpdateTransactionUrls.php b/Model/Resolver/UpdateTransactionUrls.php
index baf0d30..b884aaa 100644
--- a/Model/Resolver/UpdateTransactionUrls.php
+++ b/Model/Resolver/UpdateTransactionUrls.php
@@ -138,6 +138,22 @@ private function setTransactionUrls($cartIdMasked, $successUrl, $failureUrl)
             // Get the quote using the actual ID
             /** @var Quote $quote */
             $quote = $this->cartRepository->get($quoteId);
+            $spaceId = $quote->getPostfinancecheckoutSpaceId();
+            $transactionId = $quote->getPostfinancecheckoutTransactionId();
+
+            //At this step, if the transaction ID and space ID are empty,
+            //it could be because the enableAvailablePaymentMethodsCheck option is active,
+            //and the quote no longer has these values.
+            if (empty($spaceId) || empty($transactionId)) {
+                //Fetching the JavaScript URL here allows updating the quote
+                //with the current transaction and saving it in the session.
+                $this->transactionQuoteService->getJavaScriptUrl($quote);
+
+                //values from the session
+                $quote = $this->checkoutSession->getQuote();
+                $spaceId = $quote->getPostfinancecheckoutSpaceId();
+                $transactionId = $quote->getPostfinancecheckoutTransactionId();
+            }
 
             //$quoteSession = $this->checkoutSession->getQuote();
             /** @var \PostFinanceCheckout\Payment\Model\ResourceModel\TransactionInfo $transactionInfo */
diff --git a/Model/Webhook/Listener/AbstractOrderRelatedListener.php b/Model/Webhook/Listener/AbstractOrderRelatedListener.php
index 113b85a..2f999ea 100644
--- a/Model/Webhook/Listener/AbstractOrderRelatedListener.php
+++ b/Model/Webhook/Listener/AbstractOrderRelatedListener.php
@@ -13,6 +13,7 @@
 
 use Magento\Framework\App\ResourceConnection;
 use Magento\Framework\Exception\NotFoundException;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\Order;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
@@ -63,6 +64,12 @@ abstract class AbstractOrderRelatedListener implements ListenerInterface
      */
     private $transactionInfoRepository;
 
+    /**
+     *
+     * @var lockManager
+     */
+    protected $lockManager;
+
     /**
      *
      * @param ResourceConnection $resource
@@ -71,17 +78,24 @@ abstract class AbstractOrderRelatedListener implements ListenerInterface
      * @param OrderResourceModel $orderResourceModel
      * @param CommandPoolInterface $commandPool
      * @param TransactionInfoRepositoryInterface $transactionInfoRepository
+     * @param LockManagerInterface $lockManager
      */
-    public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
-        OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
-        TransactionInfoRepositoryInterface $transactionInfoRepository)
-    {
+    public function __construct(
+        ResourceConnection $resource,
+        LoggerInterface $logger,
+        OrderFactory $orderFactory,
+        OrderResourceModel $orderResourceModel,
+        CommandPoolInterface $commandPool,
+        TransactionInfoRepositoryInterface $transactionInfoRepository,
+        LockManagerInterface $lockManager
+    ) {
         $this->resource = $resource;
         $this->logger = $logger;
         $this->orderFactory = $orderFactory;
         $this->orderResourceModel = $orderResourceModel;
         $this->commandPool = $commandPool;
         $this->transactionInfoRepository = $transactionInfoRepository;
+        $this->lockManager = $lockManager;
     }
 
     public function execute(Request $request)
@@ -90,6 +104,7 @@ public function execute(Request $request)
         $connection = $this->beginTransaction();
         try {
             $order = $this->loadOrder($this->getOrderId($entity));
+            $transactionId = $order->getPostfinancecheckoutTransactionId();
             if ($order instanceof Order) {
                 if ($order->getPostfinancecheckoutTransactionId() != $this->getTransactionId($entity)) {
                     $this->logger->warning(
@@ -98,13 +113,15 @@ public function execute(Request $request)
                     $connection->commit();
                     return;
                 }
-                $this->lock($order);
+                $this->lock($transactionId);
                 $this->process($this->loadEntity($request), $this->loadOrder($order->getId()));
             }
+            $this->unlock($transactionId);
             $connection->commit();
         } catch (\Exception $e) {
+            $this->unlock($transactionId);
+            $connection->rollback();
             $this->logger->critical($e);
-            $connection->rollBack();
             throw $e;
         }
     }
@@ -171,17 +188,21 @@ private function getOrderId($entity)
     /**
      * Creates a lock to prevent concurrency.
      *
-     * @param Order $order
-     * @return void
+     * @return bool
+     */
+    protected function lock(string $lockId): bool
+    {
+        return $this->lockManager->lock($lockId, 1);
+    }
+
+    /**
+     * Releases our lock.
+     *
+     * @return bool
      */
-    private function lock(Order $order)
+    protected function unlock(string $lockId): bool
     {
-        $this->resource->getConnection()->update($this->resource->getTableName('sales_order'),
-            [
-                'postfinancecheckout_lock' => \date('Y-m-d H:i:s')
-            ], [
-                'entity_id = ?' => $order->getId()
-            ]);
+        return $this->lockManager->unlock($lockId);
     }
 
     /**
@@ -216,4 +237,4 @@ abstract protected function loadEntity(Request $request);
      * @return int
      */
     abstract protected function getTransactionId($entity);
-}
\ No newline at end of file
+}
diff --git a/Model/Webhook/Listener/DeliveryIndicationListener.php b/Model/Webhook/Listener/DeliveryIndicationListener.php
index 1d66952..6eb00a9 100644
--- a/Model/Webhook/Listener/DeliveryIndicationListener.php
+++ b/Model/Webhook/Listener/DeliveryIndicationListener.php
@@ -12,6 +12,7 @@
 namespace PostFinanceCheckout\Payment\Model\Webhook\Listener;
 
 use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
 use Psr\Log\LoggerInterface;
@@ -41,13 +42,15 @@ class DeliveryIndicationListener extends AbstractOrderRelatedListener
      * @param CommandPoolInterface $commandPool
      * @param TransactionInfoRepositoryInterface $transactionInfoRepository
      * @param ApiClient $apiClient
+     * @param LockManagerInterface $lockManager
      */
     public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
         OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
-        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient)
+        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient,
+        LockManagerInterface $lockManager)
     {
         parent::__construct($resource, $logger, $orderFactory, $orderResourceModel, $commandPool,
-            $transactionInfoRepository);
+            $transactionInfoRepository, $lockManager);
         $this->apiClient = $apiClient;
     }
 
@@ -73,4 +76,4 @@ protected function getTransactionId($entity)
     {
         return $entity->getLinkedTransaction();
     }
-}
\ No newline at end of file
+}
diff --git a/Model/Webhook/Listener/RefundListener.php b/Model/Webhook/Listener/RefundListener.php
index 2a44a66..0609882 100644
--- a/Model/Webhook/Listener/RefundListener.php
+++ b/Model/Webhook/Listener/RefundListener.php
@@ -12,6 +12,7 @@
 namespace PostFinanceCheckout\Payment\Model\Webhook\Listener;
 
 use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
 use Psr\Log\LoggerInterface;
@@ -41,13 +42,15 @@ class RefundListener extends AbstractOrderRelatedListener
      * @param CommandPoolInterface $commandPool
      * @param TransactionInfoRepositoryInterface $transactionInfoRepository
      * @param ApiClient $apiClient
+     * @param LockManagerInterface $lockManager
      */
     public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
         OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
-        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient)
+        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient,
+        LockManagerInterface $lockManager)
     {
         parent::__construct($resource, $logger, $orderFactory, $orderResourceModel, $commandPool,
-            $transactionInfoRepository);
+            $transactionInfoRepository, $lockManager);
         $this->apiClient = $apiClient;
     }
 
@@ -72,4 +75,4 @@ protected function getTransactionId($entity)
     {
         return $entity->getTransaction()->getId();
     }
-}
\ No newline at end of file
+}
diff --git a/Model/Webhook/Listener/TransactionCompletionListener.php b/Model/Webhook/Listener/TransactionCompletionListener.php
index 746e31d..5feb3e1 100644
--- a/Model/Webhook/Listener/TransactionCompletionListener.php
+++ b/Model/Webhook/Listener/TransactionCompletionListener.php
@@ -12,6 +12,7 @@
 namespace PostFinanceCheckout\Payment\Model\Webhook\Listener;
 
 use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
 use Psr\Log\LoggerInterface;
@@ -41,13 +42,15 @@ class TransactionCompletionListener extends AbstractOrderRelatedListener
      * @param CommandPoolInterface $commandPool
      * @param TransactionInfoRepositoryInterface $transactionInfoRepository
      * @param ApiClient $apiClient
+     * @param LockManagerInterface $lockManager
      */
     public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
         OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
-        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient)
+        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient,
+        LockManagerInterface $lockManager)
     {
         parent::__construct($resource, $logger, $orderFactory, $orderResourceModel, $commandPool,
-            $transactionInfoRepository);
+            $transactionInfoRepository, $lockManager);
         $this->apiClient = $apiClient;
     }
 
@@ -75,4 +78,4 @@ protected function getTransactionId($entity)
             ->getTransaction()
             ->getId();
     }
-}
\ No newline at end of file
+}
diff --git a/Model/Webhook/Listener/TransactionInvoiceListener.php b/Model/Webhook/Listener/TransactionInvoiceListener.php
index 000bec4..1037801 100644
--- a/Model/Webhook/Listener/TransactionInvoiceListener.php
+++ b/Model/Webhook/Listener/TransactionInvoiceListener.php
@@ -12,6 +12,7 @@
 namespace PostFinanceCheckout\Payment\Model\Webhook\Listener;
 
 use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
 use Psr\Log\LoggerInterface;
@@ -41,13 +42,15 @@ class TransactionInvoiceListener extends AbstractOrderRelatedListener
      * @param CommandPoolInterface $commandPool
      * @param TransactionInfoRepositoryInterface $transactionInfoRepository
      * @param ApiClient $apiClient
+     * @param LockManagerInterface $lockManager
      */
     public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
         OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
-        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient)
+        TransactionInfoRepositoryInterface $transactionInfoRepository, ApiClient $apiClient,
+        LockManagerInterface $lockManager)
     {
         parent::__construct($resource, $logger, $orderFactory, $orderResourceModel, $commandPool,
-            $transactionInfoRepository);
+            $transactionInfoRepository, $lockManager);
         $this->apiClient = $apiClient;
     }
 
@@ -73,4 +76,4 @@ protected function getTransactionId($entity)
     {
         return $entity->getLinkedTransaction();
     }
-}
\ No newline at end of file
+}
diff --git a/Model/Webhook/Listener/TransactionListener.php b/Model/Webhook/Listener/TransactionListener.php
index d5d7766..7f5c519 100644
--- a/Model/Webhook/Listener/TransactionListener.php
+++ b/Model/Webhook/Listener/TransactionListener.php
@@ -12,6 +12,7 @@
 namespace PostFinanceCheckout\Payment\Model\Webhook\Listener;
 
 use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Lock\LockManagerInterface;
 use Magento\Sales\Model\Order;
 use Magento\Sales\Model\OrderFactory;
 use Magento\Sales\Model\ResourceModel\Order as OrderResourceModel;
@@ -62,14 +63,20 @@ class TransactionListener extends AbstractOrderRelatedListener
      * @param TransactionInfoManagementInterface $transactionInfoManagement
      * @param ApiClient $apiClient
      * @param LoggerInterface $logger
+     * @param LockManagerInterface $lockManager
      */
-    public function __construct(ResourceConnection $resource, LoggerInterface $logger, OrderFactory $orderFactory,
-        OrderResourceModel $orderResourceModel, CommandPoolInterface $commandPool,
+    public function __construct(
+        ResourceConnection $resource,
+        LoggerInterface $logger, OrderFactory $orderFactory,
+        OrderResourceModel $orderResourceModel,
+        CommandPoolInterface $commandPool,
         TransactionInfoRepositoryInterface $transactionInfoRepository,
-        TransactionInfoManagementInterface $transactionInfoManagement, ApiClient $apiClient)
-    {
+        TransactionInfoManagementInterface $transactionInfoManagement,
+        ApiClient $apiClient,
+        LockManagerInterface $lockManager
+        ) {
         parent::__construct($resource, $logger, $orderFactory, $orderResourceModel, $commandPool,
-            $transactionInfoRepository);
+            $transactionInfoRepository, $lockManager);
         $this->transactionInfoRepository = $transactionInfoRepository;
         $this->transactionInfoManagement = $transactionInfoManagement;
         $this->apiClient = $apiClient;
@@ -115,4 +122,4 @@ protected function getTransactionId($entity)
     {
         return $entity->getId();
     }
-}
\ No newline at end of file
+}
diff --git a/Observer/ValidateAndRestoreQuote.php b/Observer/ValidateAndRestoreQuote.php
new file mode 100644
index 0000000..8033367
--- /dev/null
+++ b/Observer/ValidateAndRestoreQuote.php
@@ -0,0 +1,81 @@
+<?php
+/**
+ * PostFinance Checkout Magento 2
+ *
+ * This Magento 2 extension enables to process payments with PostFinance Checkout (https://postfinance.ch/en/business/products/e-commerce/postfinance-checkout-all-in-one.html).
+ *
+ * @package PostFinanceCheckout_Payment
+ * @author wallee AG (https://postfinance.ch/en/business/products/e-commerce/postfinance-checkout-all-in-one.html)
+ * @license http://www.apache.org/licenses/LICENSE-2.0  Apache Software License (ASL 2.0)
+
+ */
+namespace PostFinanceCheckout\Payment\Observer;
+
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Event\ObserverInterface;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Sales\Model\Order;
+use Magento\Checkout\Model\Session as CheckoutSession;
+use PostFinanceCheckout\Sdk\Model\TransactionState;
+
+/**
+ * Observer to validate and control quote restoration.
+ */
+class ValidateAndRestoreQuote implements ObserverInterface
+{
+    /**
+     * @var Order
+     */
+    private $order;
+
+    /**
+     * @var CheckoutSession
+     */
+    private $checkoutSession;
+
+    public function __construct(
+        Order $order,
+        CheckoutSession $checkoutSession
+    ) {
+        $this->order = $order;
+        $this->checkoutSession = $checkoutSession;
+    }
+
+    /**
+     * Validate and restore the quote.
+     *
+     * @param Observer $observer
+     * @throws LocalizedException
+     */
+    public function execute(Observer $observer)
+    {
+        $quote = $this->checkoutSession->getQuote();
+
+        if (!$quote || !$quote->getId()) {
+            throw new LocalizedException(__('No cart to restore.'));
+        }
+
+        // Find any orders associated with the quote
+        $orderCollection = $this->order->getCollection()
+            ->addFieldToFilter('quote_id', $quote->getId());
+
+        if ($orderCollection->getSize()) {
+            /** @var Order $order */
+            $order = $orderCollection->getFirstItem();
+
+            $orderStates = [
+                TransactionState::AUTHORIZED,
+                TransactionState::COMPLETED,
+                TransactionState::FULFILL,
+            ];
+
+            // Prevent restoring if the quote is already paid
+            if (in_array($order->getState(), $orderStates)) {
+                throw new LocalizedException(__('Your cart has already been paid for and cannot be restored.'));
+            }
+        }
+
+        // If all validations pass, let the session restore the quote
+        $this->checkoutSession->restoreQuote();
+    }
+}
diff --git a/README.md b/README.md
index fe64faa..f9962cb 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ This repository contains the Magento 2 extension that enables to process payment
 
 ## Documentation
 
-* [Documentation](https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html)
+* [Documentation](https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html)
 
 
 ## Support
@@ -39,4 +39,4 @@ We do provide special integrations for the following one step checkouts:
 
 ## License
 
-Please see the [license file](https://github.com/pfpayments/magento-2/blob/2.1.20/LICENSE) for more information.
+Please see the [license file](https://github.com/pfpayments/magento-2/blob/2.1.21/LICENSE) for more information.
diff --git a/composer.json b/composer.json
index eaf09a5..b6dd6ea 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
 		}
 	],
 	"type" : "magento2-module",
-	"version" : "2.1.20",
+	"version" : "2.1.21",
 	"require" : {
 		"php" : "~7.1.3||~7.2.0||~7.3.0||~7.4.0||~8.0||~8.1||~8.2",
 		"magento/framework" : "^102.0.0||^103.0.0",
diff --git a/docs/en/documentation.html b/docs/en/documentation.html
index 637b7e2..c51f125 100644
--- a/docs/en/documentation.html
+++ b/docs/en/documentation.html
@@ -23,7 +23,7 @@ <h2>Documentation</h2>				</div>
 		</a>
 	</li>
 	<li>
-		<a href="https://github.com/pfpayments/magento-2/releases/tag/2.1.20/">
+		<a href="https://github.com/pfpayments/magento-2/releases/tag/2.1.21/">
 			Source
 		</a>
 	</li>
diff --git a/docs/en/resource/application-user-configuration.png b/docs/en/resource/application-user-configuration.png
deleted file mode 100644
index c187595..0000000
Binary files a/docs/en/resource/application-user-configuration.png and /dev/null differ
diff --git a/docs/en/resource/payment-method-configuration.png b/docs/en/resource/payment-method-configuration.png
deleted file mode 100644
index 9983151..0000000
Binary files a/docs/en/resource/payment-method-configuration.png and /dev/null differ
diff --git a/docs/en/resource/space-configuration.png b/docs/en/resource/space-configuration.png
deleted file mode 100644
index 13306b0..0000000
Binary files a/docs/en/resource/space-configuration.png and /dev/null differ
diff --git a/etc/adminhtml/system.xml b/etc/adminhtml/system.xml
index 570e785..f666400 100644
--- a/etc/adminhtml/system.xml
+++ b/etc/adminhtml/system.xml
@@ -19,7 +19,7 @@
 			<resource>PostFinanceCheckout_Payment::config</resource>
 			<group id="information" translate="label comment" type="text" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
 				<label>Information</label>
-				<comment><![CDATA[If you need help setting up the PostFinance Checkout extension, check out the <a href="https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html" target="_blank">documentation</a>.]]></comment>
+				<comment><![CDATA[If you need help setting up the PostFinance Checkout extension, check out the <a href="https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html" target="_blank">documentation</a>.]]></comment>
 				<field id="version" translate="label" type="label" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
 					<label>Module Version</label>
 				</field>
diff --git a/etc/config.xml b/etc/config.xml
index d9c24fb..72d59bc 100644
--- a/etc/config.xml
+++ b/etc/config.xml
@@ -15,7 +15,7 @@
 	<default>
 		<postfinancecheckout_payment>
 			<information>
-				<version>2.1.20</version>
+				<version>2.1.21</version>
 				<sdk_version>4.6.0</sdk_version>
 			</information>
 			<general>
diff --git a/etc/di.xml b/etc/di.xml
index 209663b..0eb00b8 100644
--- a/etc/di.xml
+++ b/etc/di.xml
@@ -87,6 +87,16 @@
     </type>
     
     <!-- Webhook Listeners -->
+	<type name="Magento\Framework\Lock\Backend\Database">
+		<arguments>
+			<argument name="path" xsi:type="string">var/lock</argument>
+		</arguments>
+	</type>
+	<type name="PostFinanceCheckout\Payment\Model\Webhook\Listener\AbstractOrderRelatedListener">
+		<arguments>
+			<argument name="lockManager" xsi:type="object">Magento\Framework\Lock\Backend\Database</argument>
+		</arguments>
+	</type>
     <type name="PostFinanceCheckout\Payment\Model\Webhook\Listener\TransactionListener">
     	<arguments>
     		<argument name="commandPool" xsi:type="object">PostFinanceCheckoutTransactionWebhookCommandPool</argument>
diff --git a/etc/events.xml b/etc/events.xml
index e699c0b..03a1dca 100644
--- a/etc/events.xml
+++ b/etc/events.xml
@@ -63,4 +63,8 @@
 	<event name="restore_quote">
 		<observer name="postfinancecheckout_restore_quote" instance="PostFinanceCheckout\Payment\Observer\UpdateDeclinedOrderTransaction" />
 	</event>
+
+	<event name="postfinancecheckout_validate_and_restore_quote">
+		<observer name="postfinancecheckout_validate_and_restore_quote_observer" instance="PostFinanceCheckout\Payment\Observer\ValidateAndRestoreQuote" />
+	</event>
 </config>
\ No newline at end of file
diff --git a/etc/module.xml b/etc/module.xml
index 58f3a2a..bddf7ce 100644
--- a/etc/module.xml
+++ b/etc/module.xml
@@ -12,7 +12,7 @@
  */
  -->
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
-    <module name="PostFinanceCheckout_Payment" setup_version="2.1.20">
+    <module name="PostFinanceCheckout_Payment" setup_version="2.1.21">
         <sequence>
             <module name="Magento_Sales"/>
             <module name="Magento_Payment"/>
diff --git a/i18n/de_CH.csv b/i18n/de_CH.csv
index 46a326d..4460fe6 100644
--- a/i18n/de_CH.csv
+++ b/i18n/de_CH.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Lieferung halten"
 "ID required","ID erforderlich"
 "When a refund request is in a pending state, update its status to successful", "Wenn die Rückerstattung aussteht, markieren Sie sie als erfolgreich"
-"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Falls Sie Hilfe benötigen beim Einrichten der PostFinance Checkout-Erweiterung, sehen Sie sich die <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">Dokumentation</a> an."
+"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Falls Sie Hilfe benötigen beim Einrichten der PostFinance Checkout-Erweiterung, sehen Sie sich die <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">Dokumentation</a> an."
 "Inactive","Inaktiv"
 "Information","Informationen"
 "Invoice","Rechnung"
diff --git a/i18n/de_DE.csv b/i18n/de_DE.csv
index 46a326d..4460fe6 100644
--- a/i18n/de_DE.csv
+++ b/i18n/de_DE.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Lieferung halten"
 "ID required","ID erforderlich"
 "When a refund request is in a pending state, update its status to successful", "Wenn die Rückerstattung aussteht, markieren Sie sie als erfolgreich"
-"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Falls Sie Hilfe benötigen beim Einrichten der PostFinance Checkout-Erweiterung, sehen Sie sich die <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">Dokumentation</a> an."
+"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Falls Sie Hilfe benötigen beim Einrichten der PostFinance Checkout-Erweiterung, sehen Sie sich die <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">Dokumentation</a> an."
 "Inactive","Inaktiv"
 "Information","Informationen"
 "Invoice","Rechnung"
diff --git a/i18n/en_US.csv b/i18n/en_US.csv
index 5950756..44cd795 100644
--- a/i18n/en_US.csv
+++ b/i18n/en_US.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Hold Delivery"
 "ID required","ID required"
 "When a refund request is in a pending state, update its status to successful", "When a refund request is in a pending state, update its status to successful"
-"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>."
+"If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","If you need help setting up the PostFinance Checkout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>."
 "Inactive","Inactive"
 "Information","Information"
 "Invoice","Invoice"
diff --git a/i18n/fr_CH.csv b/i18n/fr_CH.csv
index 75a6537..84348ee 100644
--- a/i18n/fr_CH.csv
+++ b/i18n/fr_CH.csv
@@ -50,7 +50,7 @@
 "Gift Wrap","Papier cadeau"
 "Hold Delivery","Suspendre la livraison"
 "ID required","Pièce d'identité requise"
-"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Si vous avez besoin d'aide pour configurer l'extension postfinancecheckout, consultez la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a> an."
+"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Si vous avez besoin d'aide pour configurer l'extension postfinancecheckout, consultez la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a> an."
 "Inactive","Inactif"
 "Information","Information"
 "Invoice","Facture"
diff --git a/i18n/fr_FR.csv b/i18n/fr_FR.csv
index 16eb923..39c063b 100644
--- a/i18n/fr_FR.csv
+++ b/i18n/fr_FR.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Suspendre la livraison"
 "ID required","Pièce d'identité requise"
 "When a refund request is in a pending state, update its status to successful", "Lorsqu'une demande de remboursement est en état d'attente, mettre à jour son statut pour le marquer comme réussi"
-"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Si vous avez besoin d'aide pour configurer l'extension postfinancecheckout, consultez la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a> an."
+"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Si vous avez besoin d'aide pour configurer l'extension postfinancecheckout, consultez la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a> an."
 "Inactive","Inactif"
 "Information","Information"
 "Invoice","Facture"
diff --git a/i18n/it_CH.csv b/i18n/it_CH.csv
index 959352d..c5e0c4e 100644
--- a/i18n/it_CH.csv
+++ b/i18n/it_CH.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Sospendi la consegna"
 "ID required","ID richiesto"
 "When a refund request is in a pending state, update its status to successful", "Quando una richiesta di rimborso è in stato di attesa, contrassegnalo come eseguito con successo."
-"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Se hai bisogno di aiuto per configurare l'estensione postfinancecheckout, consulta la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentazione</a> an."
+"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Se hai bisogno di aiuto per configurare l'estensione postfinancecheckout, consulta la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentazione</a> an."
 "Inactive","Inattivo"
 "Information","Informazione"
 "Invoice","Fattura"
diff --git a/i18n/it_IT.csv b/i18n/it_IT.csv
index 959352d..c5e0c4e 100644
--- a/i18n/it_IT.csv
+++ b/i18n/it_IT.csv
@@ -51,7 +51,7 @@
 "Hold Delivery","Sospendi la consegna"
 "ID required","ID richiesto"
 "When a refund request is in a pending state, update its status to successful", "Quando una richiesta di rimborso è in stato di attesa, contrassegnalo come eseguito con successo."
-"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Se hai bisogno di aiuto per configurare l'estensione postfinancecheckout, consulta la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.20/docs/en/documentation.html"" target=""_blank"">documentazione</a> an."
+"If you need help setting up the postfinancecheckout extension, check out the <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentation</a>.","Se hai bisogno di aiuto per configurare l'estensione postfinancecheckout, consulta la <a href=""https://plugin-documentation.postfinance-checkout.ch/pfpayments/magento-2/2.1.21/docs/en/documentation.html"" target=""_blank"">documentazione</a> an."
 "Inactive","Inattivo"
 "Information","Informazione"
 "Invoice","Fattura"