Steps to reproduce

1. Make sure you have exactly one calendar
2. Create an appointment configuration
3. Delete the calendar
4. Create a new calendar
5. Open, edit and save the appointment configuration

Expected behavior

As of #3967 we already select the new calendar. So after I click Update, I assume the new calendar to be saved for the appointment config.

Actual behaviour

Visually it shows the new calendar in the multi select, but the old calendar URI is still saved. As there is only one option, the multi select is even disabled.

This is quite problematic. For one, no conflicts are detected anymore. And when an appointment is booked we can't write to the target calendar because the URI is invalid.

Calendar app version

v3.2.2

CalDAV-clients used

No response

Browser

FF

Client operating system

No response

Server operating system

No response

Web server

No response

Database engine version

No response

PHP engine version

No response

Nextcloud version

No response

Updated from an older installed version or fresh install

No response

List of activated apps

No response

Nextcloud configuration

No response

Web server error log

No response

Log file

No response

Browser log

No response

Additional info

No response