diff --git a/frontend/src/app/corpus-definitions/form/field-form/field-form.component.html b/frontend/src/app/corpus-definitions/form/field-form/field-form.component.html
index 8c8da2d99..da5c74c38 100644
--- a/frontend/src/app/corpus-definitions/form/field-form/field-form.component.html
+++ b/frontend/src/app/corpus-definitions/form/field-form/field-form.component.html
@@ -108,7 +108,7 @@ <h1 class="title">Fields</h1>
                 [class.is-disabled]="corpus.active">
                 <label class="label" id="language-label">Language (optional)</label>
                 <ia-dropdown formControlName="language" labelledBy="language-label">
-                    <span iaDropdownLabel>{{languageLabel(field)}}</span>
+                    <span iaDropdownLabel>{{languageLabel(field.get('language').value)}}</span>
                     <div iaDropdownMenu>
                         <a iaDropdownItem *ngFor="let lang of languageOptions"
                             [value]="lang.code">
diff --git a/frontend/src/app/corpus-definitions/form/field-form/field-form.component.ts b/frontend/src/app/corpus-definitions/form/field-form/field-form.component.ts
index 122144611..ba68b0cbb 100644
--- a/frontend/src/app/corpus-definitions/form/field-form/field-form.component.ts
+++ b/frontend/src/app/corpus-definitions/form/field-form/field-form.component.ts
@@ -198,9 +198,8 @@ export class FieldFormComponent implements OnChanges {
         this.dialogService.showManualPage('types-of-fields');
     }
 
-    languageLabel(field: FormGroup): string {
-        const value = field.controls.language.value;
-        return this.languageOptions.find(o => o.code == value).displayName;
+    languageLabel(code: string): string {
+        return this.languageOptions.find(o => o.code == code)?.displayName || 'Unknown';
     }
 
     addField(name: string) {
diff --git a/frontend/src/app/corpus-definitions/form/index-form/index-form.component.html b/frontend/src/app/corpus-definitions/form/index-form/index-form.component.html
index adfd14c19..c20ca00cf 100644
--- a/frontend/src/app/corpus-definitions/form/index-form/index-form.component.html
+++ b/frontend/src/app/corpus-definitions/form/index-form/index-form.component.html
@@ -98,13 +98,15 @@ <h1 class="title">Index data</h1>
             <div class="field is-grouped">
                 <div class="control">
                     <button class="button" (click)="toggleCorpusActive()"
-                        [class.is-primary]="!corpus.active">
+                        [class.is-primary]="!corpus.active"
+                        [class.is-loading]="loading$ | async">
                         {{corpus.active ? 'Deactivate' : 'Activate'}} corpus
                     </button>
                 </div>
                 <div class="control">
                     <a class="button is-primary" *ngIf="corpus.active"
-                        [routerLink]="['/search', corpus.definition.name]">
+                        [routerLink]="['/search', corpus.definition.name]"
+                        [class.is-loading]="loading$ | async">
                         <span class="icon"><fa-icon [icon]="actionIcons.search"/></span>
                         <span>Search corpus</span>
                     </a>
diff --git a/frontend/src/app/corpus-definitions/form/index-form/index-form.component.ts b/frontend/src/app/corpus-definitions/form/index-form/index-form.component.ts
index 08d4befa7..733afa348 100644
--- a/frontend/src/app/corpus-definitions/form/index-form/index-form.component.ts
+++ b/frontend/src/app/corpus-definitions/form/index-form/index-form.component.ts
@@ -4,7 +4,7 @@ import { APIIndexHealth, isComplete, JobStatus } from '@models/indexing';
 import { ApiService, CorpusService } from '@services';
 import { actionIcons } from '@shared/icons';
 import * as _ from 'lodash';
-import { map, Subject, switchMap, merge, filter } from 'rxjs';
+import { map, Subject, switchMap, merge, filter, BehaviorSubject } from 'rxjs';
 
 /** Possible states for the interface of this component */
 type DisplayState = {
@@ -85,9 +85,11 @@ export class IndexFormComponent implements OnChanges, OnDestroy {
 
     state$ = new Subject<DisplayState>;
     destroy$ = new Subject<void>();
+    loading$ = new BehaviorSubject<boolean>(false);
 
     actionIcons = actionIcons;
 
+
     private jobID: number;
     private stopping$ = new Subject<boolean>();
 
@@ -138,7 +140,8 @@ export class IndexFormComponent implements OnChanges, OnDestroy {
 
     toggleCorpusActive() {
         this.corpus.active = !this.corpus.active;
-        this.corpus.save();
+        this.loading$.next(true);
+        this.corpus.save().subscribe(() => this.loading$.next(false));
     }
 
     stateClass(state: DisplayState) {
diff --git a/frontend/src/app/models/corpus-definition.ts b/frontend/src/app/models/corpus-definition.ts
index 01b578e8b..4bb4ef45e 100644
--- a/frontend/src/app/models/corpus-definition.ts
+++ b/frontend/src/app/models/corpus-definition.ts
@@ -1,7 +1,7 @@
 import * as _ from 'lodash';
 import { ApiService, CorpusService } from '@services';
-import { BehaviorSubject, Observable } from 'rxjs';
-import { filter, share, switchMap, tap } from 'rxjs/operators';
+import { BehaviorSubject, from, Observable } from 'rxjs';
+import { delayWhen, filter, shareReplay, tap } from 'rxjs/operators';
 import { findByName } from '@app/utils/utils';
 
 export type Delimiter = ',' | ';' | '\t';
@@ -153,15 +153,13 @@ export class CorpusDefinition {
         const request$ = this.id
             ? this.apiService.updateCorpus(this.id, data)
             : this.apiService.createCorpus(data);
-        const result$ = request$.pipe(share());
-
-        result$.subscribe((result) => this.setFromAPIData(result));
-        // refresh corpus data if applicable
-        result$.pipe(
-            switchMap(() => this.requireCorpusRefresh()),
-            filter(_.identity)
-        ).subscribe(() => this.corpusService.get(true));
+        const result$ = request$.pipe(
+            tap(result => this.setFromAPIData(result)),
+            delayWhen(() => this.refreshCorpora()),
+            shareReplay(1),
+        );
 
+        result$.subscribe(); // subscribe to execute request(s)
         return result$;
     }
 
@@ -200,6 +198,13 @@ export class CorpusDefinition {
         }
         return Promise.resolve(false);
     }
+
+    /** refresh searchable corpora if needed */
+    private refreshCorpora(): Observable<any> {
+        return from(this.requireCorpusRefresh().then(
+            refresh => refresh ? this.corpusService.get(refresh) : Promise.resolve(undefined)
+        ));
+    }
 };
 
 export const FIELD_TYPE_OPTIONS: {