Hello, I have been using the same Graphics card Titan Xp with Ubuntu 16.04, 18.04, 20.04 with no problem. It seems a recent upgrade broke the Xorg server. X server will fail immediately and make a blank screen (no signal). I have a few cards around and can confirm the card hardware is good. The current driver is 455, but I tried 440, 450 before, with the same symptom.
I removed and reinstalled Nvidia drivers, tried the PPA driver, but that did not help.
The command nvidia-smi works, so it seems both the driver and the runtime all works?
Can you help? What other information I should look into? Thank you.