At a guess:
1. sudo apt remove nvidia-driver-535 nvidia-dkms-535 2. sudo apt purge 3. Reboot. 4. Open the 'Additional Drivers' app in GNOME and use it to reinstall. 5. Reboot again.
At a guess:
1. sudo apt remove nvidia-driver-535 nvidia-dkms-535
2. sudo apt purge
3. Reboot.
4. Open the 'Additional Drivers' app in GNOME and use it to reinstall.
5. Reboot again.