Found the cause. Disabling screen traces seems to fix it.
Guess I need to add this one to the config:
r.Lumen.ScreenProbeGather.ScreenTraces 0
Although I have no idea if it has any other “hidden” consequences since I see no visual difference between 0/1, only those white “artifacts” disappear
Thanks Arkiras, you pushed me in the right direction so I started unchecking and checking everything in “stat” tab and found it