Im on xbox and i also had this happen this morning.
Using stock A320, i couldnt arm the air brake with TBV1 binding until i had selected it with the mouse.
I restarted the flight a couple times as sometimes my controls dont show on screen with PG on 
.
Im not sure why but i been having a few wierd issues lately with stock planes and the base program.
I disabled the on screen system notifications a while back when i became more familiar with some 3rd party craft but now iv been learning some of the others o cant for the life of me turn them back on again 
Plus ATC must be drunk since the last update as they have me going up and down like a yo-yo