Windows Start Menu Tiles

I have Studio 15 B6 installed on a Maingear computer, Windows 10 Pro x64 with 2 nVidia gtx 690 video cards. Very often (but not always) when using the Fusion module, the Windows 10 tiles on the start menu go blank (no pictures or text). I have to either reboot the computer or restart windows explorer to get the tiles back.

Is this a but or do I have a different problem. I noticed the behavior with b2 to b4 but not b5.

Thanks for your help.

Bill Byrnes