Error "Cannot update non-existing record" when using Redis as Session Storage

[bugskarl]

the Captcha field on the "Registration: Create User" plugin requires an active fe session. this is resulting in an error "Cannot update non-existing record" when using redis as frontend session store:

• TYPO3 v13.4.24
• sf_register v13.2.2
• pugin: sfregister_create
• field: captcha
• redis fe session backend

i did open a core bug on this matter: https://forge.typo3.org/issues/108995

temp solution is to fixate the anonymous session by xclassing the session object:

class Session extends \Evoweb\SfRegister\Services\Session
{
    public function __construct()
    {
        parent::__construct();

        // force storing anonymous sessions for captcha checking to work
        if ($this->session->isAnonymous() && !$this->session->isPermanent()) {
            $this->userSessionManager->fixateAnonymousSession($this->session);
        }
    }
}