GDM causes keyboard and mouse to freeze on login screen of Manjaro
In the last few days, arch forums have posts with problems like this one. A common feature in all of them is that everybody did sudo pacman -Syu
and immediately after rebooting keyboard and mouse stop working on the login screen (they work before reaching there).
To reproduce, acquire Kernel: 5.15.108-1-MANJARO
and gnome-shell: 43.4
or simply update to the latest (because this is not patched yet).
Somebody managed to fix it but their solution is not general.