Unable to map button to Y and select

I’ve started building a raspberry pi3 arcade bartop and now mapping buttons and joysticks using a xin mo controller encoder. All buttons and sticks are recognized on the pc, retroarch recognizes the xin mo. I’m having an issue with mapping any button to Y and select in retroarch. I’ve configured all other button to x,b and a and the joysticks mapped to up/down/left/right. When I try mapping any button to Y or select I get (key:) and that’s it. I’ve mapped buttons and sticks in emulation station with no problems. Anyone know where I’m going wrong or what’s happening?

Cheers much