My goodness! Thank you so much for your suggestions and clarifications! I reinstalled, and I'm officially in love with this port. Hoping to make this my daily driver someday.

I installed UT next on my Fairphone 5 to have a look. Last night I ran the 207 update through the settings menu. I'm not sure if the problems arose from that or some other thing I did (downloaded a couple of music files and played them on the phone, tried to open Libertine, had a look at most of the pre installed apps), but now every single app I try opening crashes at the opening screen, including the Settings app. The desktop environment still seems to run smoothly though, and the morning alarm went off as planned. It just can't run any apps.

Is there some debugging and maybe fixing I could run through my computer (old Thinkpad running Xubuntu), could I simply reinstall through the UBports Installer, or do I need to reinstall the correct Android version before running the UBports installer again?

I would of course love to fix the problem, but I'm happy reinstalling UT too, maybe trying the 20.04 version.