When dealing with 3d layers, you have to pay attention to the Z-position of every layer, as well as their rotation, or else things may start intersecting. You can adjust a layer's Z position to see if that helps fix your issue, as DJ suggested. Since you're just dealing with a simple appearance here, you can then adjust scale to compensate. There is also a workaround to force the layers to render as you would expect them to in a 2d comp. If you insert a 2d adjustment layer between the layers that are intersecting, it should break the intersection. (This can introduce other issues, though, if you're trying to really take advantage of the 3d capabilities.)
... View more