144Hz not available

Welcome to the forum!

So from what I can tell, there seems to be an issue now with your Nvidia drivers in relation to your display settings. This has been an issue lately due to some recent updates. If you run a uname -r , and if you're running kernel 6.8 that would be the case depending on if you're running nvidia version 545:

This would be the first thing that I would check if anything here matches up and is a known issue.