i'll try to post again, because for some reason the other one didn't go through..but what you're experiencing is the z-fighting phenomenon. it's prevalent throughout most (if not all) the maps and even some ready rooms (see veil's ready-room floor). it seems to be most obvious on infestation when set to minimal, but i've also seen it with planar objects like posters on walls.
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But it looks like a clipping issue