Meeting updates not sent due to SCHEDULE-AGENT not reset when previously set by other client

Steps to reproduce

1. Create calendar event with another client like TB (make sure scheduling is configured to client) so that TB sets the SCHEDULE-AGENT parameters on Organizer and ATTENDEE
2. Use Calendar App to modify event, this should cause a iTip/iMip update but does not due to SCHEDULE-AGENT=CLIENT

Expected behavior

SCHEDULE-AGENT should be changed to SERVER or removed so that invitations are sent

Actual behavior

No invitation are sent

Calendar app version

No response

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

No files, tests, or entry points are named. Start by reproducing the event flow with another CalDAV client setting SCHEDULE-AGENT=CLIENT, then modify the event in Calendar App and inspect whether an iTip/iMip update is sent. Done means SCHEDULE-AGENT is changed to SERVER or removed and invitations are sent.