Nvidia RTX3050 on Debian stable (12) with proprietary X.Org nvidia driver 535.216.01, connected to TV via HDMI through audio receiver. Valid modes are correctly parsed from EDID and I can set resolution to 3840x2160 @120Hz. But when I turn off the TV and turn it back on, no signal is detected. I must switch to a virtual console and back to the graphical console to get the X.Org desktop to display again.
3840x2160 @120Hz O.O !!!
I’ve had that problem with nvidia/debian before
I had a dual monitor set up with a tv screen and a pc monitor, and I had to reload the display settings every time the tv screen switched off, even though I had saved the settings for the dual monitor set up already, which should have reloaded when the tv screen turned on, instead it did some auto-detection, ignored my settings, and presented me with a black screen.
There are quite a few bugs like this, and depending on your desktop environment, the host OS, there is different behavior, and different considerations involved.
For me the fix, was simply, to load the display settings, and set it up manually to how I wanted it. Sometimes I had to do this multiple times, and it never worked cleanly, until I got it working, and left the display settings alone. I think I had that exact experience with xfce bullseye about a year ago.
Not only couldn’t it handle having the tv screen turn off with the dual monitor display settings active, but on reboot it would also fail to work, and I’d have to unplug the tv screen, or try to use the tv screen, which became the default and only working display, to fix the display settings again.
Of course I looked up solutions to this problem, which basically resulted in no helpful info whatsoever.