Or can it be that literally I had a short term hardware error in my card
because of running in this hot summer for very long periods. I could be ram
corruption too that just got solved now for some reason. Also I can image zram
and hiz maybe seperate small static rams that were not used for years so it had
to get some warmup time - quite the opposite of the overuse?

In any ways. The performance is sometime a bit better, sometimes measurably
better and now I do not see any glitches. Weird. I think I make this bug to be
a "minor" one as maybe it is not really a real bug?