Bulding "isometric" cube — strange layer overlapping

Hi there, 

I create a nearly isometric cube. It is a set of 3D layers and a deeply zoomed camera with a huge focal length.

The problem is, that despite the sides being set precisely, when I rotate this cube, the layers overlap in a strange way. The problem can be partially resolved by rearranging the layer-order, but when the cube is rotated, the issue appears on the other side.

This behaviour occurs only when the "isometric camera" is active. In Custom view mode the cube works correctly. In C4D renderer it is OK as well, but gradients are gone — I need them in this project. 

What's the nature of this issue? And is there some workaround to it except switching to C4D renderer?

Here is the project-file:
https://www.dropbox.com/s/xuo15eds27na37q/Iso%20Cube%20%283D%29.aep?dl=0

Thank you!