Going back to login screen is concerning at the very least, like it wasn’t your game crashing, but the Xserver or Plasma, which could potentially be a kernel bug (with amdgpu) or Mesa, or Xorg…
Try to gather some logs as it happens. See if it’s kernel/amdgpu thing
<span style="color:#323232;">sudo dmesg
</span>
See if it’s something in user space crashing (plasma session? Xorg?)
<span style="color:#323232;">journalctl -b # then press capital G to jump to the end of logs
</span>
I’d try to:
trying the Plasma Wayland session to see if it’s not Xorg (should be straightforward given that you’re on AMD/RDNA2).