Unable to use B or Start buttons on controller.

[PepperTroopa]

I'm trying to use an 8Bitdo NES30 Pro Controller to play this game. I mapped all of the buttons in Big Picture Mode, but it seems that only the directional buttons and X & A buttons work. The start button and B button do absolutely nothing. I am unable to exit out of any menus. Any way I can fix this?

[[DBH].Whismerhill.{SSgt}]

*I suppose you could try using x360ce