I have PR by me against a repo of my own. During further work, I amended a commit, added another one, and force-pushed everything to the related branch. The branch also is fine – the latest commit is present – but the PR says "This pull request is broken due to missing fork information.". Sounds like https://github.com/go-gitea/gitea/issues/11196, the affected PR is https://codeberg.org/blizzz/harbour-nextcloud-talk/pulls/19
I suppose I can recreate, no biggie, unless someone would like to have a look at this?