I am this exact case and it’s getting better. A month ago I installed Arch on my Nvidia desktop and it had multiple problems: returning from sleep, really bad cursor lag hitches, video would freeze at random, applications would flicker, etc. Nowadays most of it is gone, unfortunately the really bad freezes after changing resolution on monitors are still there though
Are they based on Firefox ESR? That made me quit Floorp, it was pretty disappointing to be on a legacy reskin of Firefox.