Local Calendar events disappeared

Question

I tried to remove a repeating calendar event from the unsynchronized Local Calendar account using the stock calendar app¹. At first I thought that all calendar events were deleted (not just the repeating event), because the calendar was now completely empty.

But then I realized that I could still export all calender events using Calendar Import - Export. And sure enough, inspecting /data/data/com.android.providers.calendar/databases/calendar.db revealed that all events were still there.

I tried the following to have the events displayed again in the calendar app:

• Checking the proper calendar account was selected (it was, there is only one)
• Using another app: DigiCal also displays no events (which it previously did)
• Resetting the calendar app
• Restoring the calendar app from a backup
• Clearing the cache (not the data) of the Calendar Storage app that provides the database file mentioned above
• Manually adding a new event works, but all other events are still missing. Exporting all events again now also includes this new event.

Nothing of the above fixed the problem. I could purge the data from the Calendar Storage app, clearing the DB and importing all events that I previously exported. But I'm hestitant to do so without understanding what's gone wrong and how I can properly fix it so it won't happen again, and I'm not sure this would even work.

What's going on here? How can I have all the events displayed again?

¹ I'm running Xiaomi.eu's MIUI 12.5.2.0

Answer 1

Absent other ideas, I purged the data from the Calendar Storage and reimported the events.

This worked: All events are now displayed again, though it remains unclear what actually went wrong in the first place. Let's hope this won't happen again.