(In reply to Wolfgang Bauer from comment #10) > (In reply to Stefan Dirsch from comment #9) > > Then it needs to be some generic bug in > > Plasma, unrelated to the driver. Back to KDE. > I still doubt that, TBH. > > But, does it help if you delete the folder ~/.cache/? > > That's my only idea at the moment. > > If not, please also try on a fresh user account. Thanks. I moved ~/.cache to ~/old-dot-cache, and after the next login the issue is gone.