Today, after a pacman -Syu, after reboot I wasn't anymore able to login.
After the plymouth screen, instead of presenting the login screen the system was showing a black screen.
Restoring a snapshot the problem disappeared, but appeared again after re-upgrading.
I thought to remove the splash from grub parameters and this was working (able to login).
I checked the pacman log and found (amongst the rest)
upgraded sddm (0.19.0-4 -> 0.19.0-5)
So, I went back to the previous version with
sudo pacman -U /var/cache/pacman/pkg/sddm-0.19.0-4-x86_64.pkg.tar.zst
and now everything is back to normal.
What can I do now, and for future updates (to avoid this from occurring again)?
Thanks in advance!