The file below illustrates the problem. Create a copper area on top and bottom of board.  Create some vias in between. Mask the top and bottom solder mask (with a rectangle) as you would if you wanted bare copper to solder a mosfet to for thermal reasons. Render the photo or gerber.  The bottom surface correctly renders. The top does not. The vias are not visible. [https://drive.google.com/open?id=1c2K32OgADLJ835bzxWHK_RrQzdrTMS1Q](https://drive.google.com/open?id=1c2K32OgADLJ835bzxWHK_RrQzdrTMS1Q)