Ok after doing some more work on the project, I noticed that when hiding (with the eye icon) all but the hair and the head texture set, the problem goes away as well. My suspicion is that this might be some optimization thing Substance is doing or something else related to that, the scene has about 150 objects and 42 4k…
Oh thanks for second guessing that, even if it might be unrelated to the issue. I couldn't find much about what shader to use for what situations. The character is for real-time use in unreal and marmoset with the PBR roughness workflow. The charcter won't have any alpha transparency, but some parts are glass. So you're…