EDIT: I kinda solved it by installing Wayland (on my 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)
I'm using 75 AUR packages without any issues and I've been using Manjaro for 4 years. But I'm really worried now that you've said that. 😬 When should I begin to expect AUR trouble? Does it happen on the 5th year? What if I reinstall, do I get another 4 years?
Good for you. Have you heard about anecdotal evidence already?
I'm hearing anecdotal evidence all the time, from people who avoid using AUR packages. I'm a person who uses them, and uses a lot of them, and has been doing it for extended periods of time. That's not anecdotal, it's concrete proof.