Reminders for calendar events are delayed

[ThracianKnight1907]

• [x] This is not a feature request (existing functionality does not work, not missing functionality). I will request features on forum or via support.
• [x] I've searched and did not find a similar issue.

Describe the bug Notifications for calendar events reminders are delayed

To Reproduce Steps to reproduce the behavior:

1. Create an event
2. Set a reminder to e.g. 10 minutes before
3. The reminder won't come 10 minutes before, but at a random (?) time (before or after the event).

Expected behavior Reminder comes at the time it was set

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Fedora
• Desktop Environment, if applicable (on Linux): Gnome 3.38.1
• Version 33 Add any other context about the problem here. I'm using the flatpak version. This issue doesn't happen on ios or android.