Hey-
I am not an experienced linux user, and am relatively new to Fedora myself; however, I have been experiencing this same issue very frequently since switching to Fedora 43 (see my related post for details).
I believe this is an unresolved kernel-level amdgpu driver bug which is particularly prevalent in multi-monitor and/or high refresh rate / VRR enabled monitor setups, although this is speculation based upon my surface-level research of the issue.
I found this Gitlab thread describing this same issue- the thread has been open since 2023 but is still very active, with reports as late as kernel 6.19. There are many posts speculating as to the cause and suggesting various potential fixes/workarounds:
One of the suggested workarounds is to disable the atomic KMS API by provisioning an environment variable to force the mutter KMS mode to “simple”. I implemented this workaround three days ago, and have had no system freezes ever since. I do not know what tradeoffs there are by using simple vs. atomic; however, I have not noticed any performance or functionality impacts.
The environment variable can be provisioned persistently system-wide by executing the following two commands from terminal, and then rebooting:
sudo mkdir -p /etc/environment.d
echo "MUTTER_DEBUG_FORCE_KMS_MODE=simple" | sudo tee /etc/environment.d/mutter-kms.conf
NOTE: When I did this, for some reason the ability to lock my system (both through gnome GUI and Super + L shortcuts) was disabled. I fixed this by running the following command, which fixed the issue for me:
gsettings set org.gnome.desktop.lockdown disable-lock-screen false
So far this has fixed the issue for me; however, its only been three days of stability so I can only hope it persists. If you decide to try this, let me know how it goes!
-Benjamin