I tried Manjaro for a while and had the same Plasma issues with KDE, which originate with the Nvidia drivers. Unfortunately, Manjaro is pretty poorly maintained and always manages to break itself within a couple months.

If you’re looking a for a super stable and reliable Arch-based distro, try Garuda. I’ve been running Garuda with KDE for over 7 months without a single issue.

Please, by all means, show us the way and lead by example, instead of being a second rate arm-chair general behind the keyboard.