Great! Now you have your NVIDIA graphics card tagged as [MASTER].
Could you check output of command "loginctl show-seat seat0" once again? Does it show CanGraphical=yes now? Did lightdm goes back to normal?
Great! Now you have your NVIDIA graphics card tagged as [MASTER].
Could you check output of command "loginctl show-seat seat0" once again? Does it show CanGraphical=yes now? Did lightdm goes back to normal?