It's not #peertube 's day. I get a notification that 8.1.1 is out. The update script installs 8.1.2. I see no changelog for the .2. I check out the github and it lists this version's changes as mostly bugfixes, especially fixing the thumbnails.
The update goes through normally and I start Peertube. Now all the thumbnails are broken. Regenerate thumbnails does not fix them, but instead results in a lot of error messages about missing thumbnail files.
As there's no updated procedure available, I had to revert back to 8.1 that at least has the thumbnails working.