EDIT: I kinda solved it by installing Wayland (with Nvidia card, Ouch!) to replace Xorg. Not sure if this is gonna last though. Perhaps Manjaro is the one I'm gonna throw out FIRST if anything happens from now on.
What should be the first line of defense? Timeshift?
This happened after I installed AUR package masterpdfeditor and 2 applications from github (some hashing algorithm programs, I think they were "Dilithium" and "Latice-based-cryptography-main", one of them was provided by NIST.)
If using GUI: I login, black screen for few seconds, then back at login screen.
If going to ctrl+alt+f2, login successful, then startx, see picture provided (higher quality).
I tried adding a new user, but result is the same.
I have a live usb to do the Timeshift. (I can also chroot if necessary... But I'm not extremely professional)
If you have it setup timeshift should work...
But please know that the AUR + Manjaro is not a supported or recommend combination. The AUR is intended to be used with the official Arch repos; Manjaro repos are often weeks or sometimes even up to a month behind. Even the Manjaro devs put a warning for this reason.
Not only that, the Manjaro base packages often aren't even built with the same flags as Arch base packages; which is probably what happened here.
Consider using EndeavorOS or
archinstall, else this won't be the last time something like this happens.