No attendee response email sent when responding via link

Steps to reproduce

1. Make sure to enable "Send invitations to attendees" in /settings/admin/groupware
2. Create a calendar event and invite Person A.
3. Person A gets an invite email.
4. Let Person A click on "Accept" or "Decline".
5. See how you as the inviting person don't get a response email.

Expected behavior

You should get an email about the response of the invited person. Same thing for changes in attendance that the invited person might make later.

Actual behavior

Response emails are just sent when the invited person is responding via a CalDAV client like Apple Calendar or the Nextcloud web interface - but not if they respond through the links in the invitation email.

Calendar app version

5.2.2

CalDAV-clients used

No response

Browser

No response

Client operating system

No response

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

No response

Updated from an older installed version or fresh install

None

List of activated apps

Nextcloud configuration

Web server error log

Log file

Browser log

Additional info

No response

Start at the invitation email response links and compare their Accept or Decline handling with the CalDAV and Nextcloud web-interface response paths. Verify that the inviting person receives response emails for initial responses and later attendance changes made through the links.