Mainstage not responding to incoming program changes

Mainstage 3.6.1 responds to MIDI program changes from my Yamaha Motif XS7 at home, but when I'm using another controller, usually a Motif XF, everything works but MainStage won't respond to the incoming program changes. They look exactly the same in the incoming Midi Monitor window, so what gives? It's like MainStage has some setting where it recognizes my Motif XS as the only true "Master Keyboard", but when I assign that same keyboard to an incoming Motif XF, it won't recognize the program changes even though it's sending the same thing. Driving me nuts; I often do gigs using backline rented keyboards that should work, but I have to change all the patches manually on the computer...