Not sure whether I selected the right category, but either way.
I noticed this bug this morning while I was, well, building stuff. This did happen before, but I managed to cope with it, now it happens every single time. I really cannot explain it with words, so I’ll post some screenshots.
This is just an example, but it does show what happens. Consists of exactly one part and one negative part.
When I union it, this happens. The dark gray surfaces are mainly unaffected by light, except for sunlight, which also occurs rarely.
As I said earlier, this didn’t happen as often before, and even more rarely on the complex unions. I must also say, it happens strictly on the faces that are at the right angle. Really hope it’ll get fixed and stuff