Help! How do I remove these white areas from depressured cloth?

I have a short animation of a cloth cube depressurizing to show a logo reveal. I'm trying to edit this animation, so the white splotches are not on the final render. Someone suggested there is an issue with two surfaces on the cloth interacting with each other, but I don't know where to fix it. I tried lowering and increasing the friction and the distance under self-collisions, but the effect is still there. I'd love any tips for how to fix this !