Removing Corrupt CalDav Object

I’ve been dealing with an error with my phone syncing two of my Nextcloud calendars using DAVx5 sync on Android. Every time it tries to sync, it gets a 404 error and the Nextcloud logs are empty. Today I tried to export the calendar and got a server error. Looking at the logs, it appears that a calendar object has become corrupted. The PHP error looks like it’s trying to index an array on a null variable. I’m not too familiar with the CalDav protocol but it sounds like an object in my calendar is supposed to contain an array but it is instead null and the server doesn’t know how to handle this situation.

    "message": "str_replace(): Argument #3 ($subject) must be of type array|string, null given",

When I view the calendar in Nextcloud, it won’t show any events for July - November 2022 and the loading spinner next to the calendar continues to spin indefinitely.

Is there a way to locate these corrupted calendar objects and just delete them? I’d like to not lose the whole calendar.

Full log entries are here: