Account not showing accepted calendar events

Steps to reproduce

1.Have a user on NC send a calendar invite to user X
2.Have user X accept it via email

Expected behavior

Event would show up for the user in
Calendar WebUI
Recent activity in dashboard
Android calendars pulling in events through davx5

Actual behaviour

Event doesn't show up for user X anywhere.
However the sender will still see the event as accepted

This works for all (that I have tested) other users, just not user X.
I can have user A send an event to B and X, and it work perfectly for B.

Or have user X send it to any other user, and it'll show up just fine for that user.

Calendar app version

5.0.1

CalDAV-clients used

Davx5, etar, NextCloud WebUI

Browser

No response

Client operating system

No response

Server operating system

Alpine linux

Web server

Nginx

Database engine version

MariaDB

PHP engine version

PHP 8.2

Nextcloud version

30.0.2

Updated from an older installed version or fresh install

Updated from an older version

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

No source file or test is identified in the report. Reproduce the invite and acceptance steps, then compare user X with a working recipient across Calendar WebUI, dashboard activity, and DAVx5; done means accepted events appear for X in all listed clients.