I have the same card on Debian 12. All you need is to install nvidia-driver
and firmware-linux
, then reboot. (assuming you're using the default kernel)
If you still have the same issues, it's not a driver problem.
But I had the exact same problem with KDE, on a default Debian 12 install. Debian Gnome didn't crash. Neither did KDE on other distros.
My best guess is you need to switch to another DE, Debian release branch, or distro. After some quick googling, Debian Stable+KDE+nVidia seems to be a combination that just doesn't work well. Sadly, this is still a reality in the Linux world. With so many moving parts built by independent projects, some combinations are broken.