Hi,
I am sorry but I can't share it. It also happens when I try to final render.
Please try to test with any more complex cad data converted to FBX and imported to C4D with Normal Tag.
I am sure it will be the same issue. It was not only on this part. It's almost on every object with hard edges. It happens only next to the edges so big smooth surface is not affected.
Best,
Mac