I also used to have the problems reported by Daniel but in my case it seems they stopped happening since Qt update to 5.15.7 (with KDE patches applied to qtbase and qtdeclarative modules).
Currently I didn't have any issues at all in the last 5 days on two computers (with Intel and AMD/ATI chipsets) where they happened once every 1-2 days. I also run many times Oleg's reproducer without any issue. It may just be a coincidence, BTW I also updated Mesa to 22.2.3 and KDE Plasma to 5.26.3, are you all using such releases?
I also used to have the problems reported by Daniel but in my case it seems they stopped happening since Qt update to 5.15.7 (with KDE patches applied to qtbase and qtdeclarative modules).
Currently I didn't have any issues at all in the last 5 days on two computers (with Intel and AMD/ATI chipsets) where they happened once every 1-2 days. I also run many times Oleg's reproducer without any issue. It may just be a coincidence, BTW I also updated Mesa to 22.2.3 and KDE Plasma to 5.26.3, are you all using such releases?