Don't remember what packages caused problems for me but I had to repair it via tty quite a time. Not updating AUR packages automatically is actually a nice workaround to prevent system breakage which I was also doing it, until it started to cause problems more often. Maybe they fixed it I don't know (though highly doubt it because of the way they do it), haven't used Manjaro for 4 years. Then I thought about that, why would I need to deal with these kind of things if I can use my system up-to-date with every part of it. No one uses Manjaro because it's stable, people use it because it was the only "Arch with GUI" they know at the time. Now we have a lot of these and some of them are better than Manjaro. But again, if you're happy with Manjaro there is no need to change. I was happy until I wasn't because of Manjaro's structural problems (like they nuked AUR once). It's not a bad thing to recommend a better option if you know one.