Hi, eko1!
I have only
check for space
May be it not the case to think only. It’s time to sync with reality: to be sure that it is not a free space problem.
and
to update
Installed kernel: 5.12 but I have tried 5.10 and 5.9 from grub, same results.
Why only that selection? 5.9 and 5.12 are End-of-life. current 5.10 has bugfix number not less than 70 in the stable updates branch.
Did you know that already was 5.13 and now it is EoL but for a couple of weeks will be still available in Manjaro? Also 5.14 is current, 5.15 is available, but for now it is currently in beta.
May be using other kernel versions could fix that keyboard behavior.
But first, may to find a fresh server to get updates from and to update all the packages you have?
If to update, consider to do this:
sudo pacman-mirrors -B unstable -a -c Sweden -P https
(or any your country)
and than
sudo pacman -Syyu
to reboot and than to pdate AUR packages (if you have them)
pamac update -a --force-refresh
May be to use other keyboard meantime of you have it?
Or to do all via GUI: may be login screen have a virtual (on-screen) keyboard.
Or to try to load Live USB (may be the same keyboard will work) and “chroot” and to check out journalctl logs, to update the installed system from within Live USB session.
“chroot” - I mean “manjaro-chroot”: Login Failed on Manjaro linux session - #7 by Mirdarthos
the same instruction, but change password stuff to OS update stuff suggested in this my post.
suggestions.