I have a similar issue specific to my Intel graphics, debian 12, and kde. It’s fixed in the newer kernel in debian Trixie. In my case I was able to set up a keybind to ctrl-alt-backspace which kills the graphics server. I have to catch it quick or it’ll lock up completely, but it’s something to try. I’m on 15 days uptime now I’ve probably had to do that about 5 times.