I don't know. But it's probably the QT libraries on 20.04.2 (the version I had after updates) which got corrupted along the way, maybe ? I followed the same steps on ubuntu 21 and it worked fine !
Maybe it's the small updates each 2 weeks or so, which corrupted QT, I will probably never update after a working install ever. If it works I will keep it that way and disable every update that may break a system. (ironically, much like I would do on windows 10
)
Almost 5 posts before I was talking about how Ubuntu is way more stable than Arch/Manjaro..........
I guess I was wrong, sorry Arch users, I will join you when I find the time !
EDIT : YOU WILL NEVER BELIEVE IT, but minutes after I finished typing this post, I wanted to minimize firefox, and the whole system froze/bugged and I got logged out !!!! I know 21.04 swiched to wayland from Xorg, it might be why. But that timing ! it's almost like ubuntu got angry I wanted to switch to Arch lol.