It looks like you have two or more layers sharing the same plane. Offset each plane by 1 pixel in Z space. This is necessary when using the C4D rendering engine, and I recommend it when using Classic 3D.
Start at the top and move each successive layer 1 pixel in Z. Your problem should go away. It is easiest to offset the Z position one pixel if you select all but what would be the top layer, hold down the Shift key, then parent them all to the top layer. This snaps all layers to the same position. Now open up the Position property of all of the child layers. They will all show 0, 0, 0 for Position. Moving each successive layer behind the other by one pixel is easy and accurate when using this trick.
I don't see any extrusion or bending in your sample. I never use the C4D rendering engine unless I take advantage of extrusion for shape and text or layer bending for other layers.