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)
ah classic mistake of installing AUR packages on manjaro. been there done that. check your logs and search for errors, it probably overwrote/deleted some xorg config that you must either manually add back or regenerate. sorry i can't help further im a linux noobie but that was my issue when this happened to me.
Why would a package called "masterpdfcreator" overwrite the x conf? I don't think the AUR packages have anything to do with the problem.
ah sorry it's more accurate to say it can "break" your xorg config cause that was my case. looking at this package it has libgl as one of its dependencies. as i have said i'm not familiar with how exactly it works but it can probably mess with your graphics drivers.