I have a Librem 15 v3 with a freshly air cleaned keyboard [German Layout] All of a sudden, when I press the V key, the Alt Gr key is also activated, and „is registered on the keys. When I press just the Alt Gr key „ is registered as well. When pressing B the Altis also registered which triggers window depended action, for example in the browser the bookmarks tab opens. Same happens when pressing Alt.
The keyboard is perfectly clean and working just fine. I think this is a software issue.
I have similar issues with my 13v3 German keyboard (Partial keyboard failure). The problem in my case started saturday/sunday and has a part of the keyboard acting like the numpad. Can you check whether the problem, like in my case, starts after logging into your user account? Also, in my case the accessibility feature “mouse keys” alters the problem. Maybe that would confirm that we have the same or a different underlying problem.