I had similar issues on 20.04, where an update restarted locked in lo-res graphics. I navigated to Menu\Administration\Software&Updates\AdditionalDrivers and selected the X.Org driver instead of NVIDIA and normal service resumed.
Can't Access NVIDIA Drivers After Update
I had similar issues on 20.04, where an update restarted locked in lo-res graphics. I navigated to Menu\Administration\Software&Updates\AdditionalDrivers and selected the X.Org driver instead of NVIDIA and normal service resumed.