Thank you very much for your answer. I was not aware of the dist-upgrade being required now, so I did that, but unfortunately it did not change anything after a reboot. I reinstalled nvidia-detect to see if that caused any issues, but that did not seem to be the case. Your last step I actually already did some time ago, and I tried to do the same no. Unfortunately that also did not seem to have fixed the problem. The nvidia graphics settings software is still installed, but it only shows some very limited control options compared to how it used to be. This is what that program looks like now: