Was there anything bound to the right most toggle switch??
I’ve had the Alpha and Bravo units for two weeks now and not yet experienced this issue - Avionics 1 switch has always worked just fine for me.
Notice that I did say the word ‘yet’…!!
It’s also worth double checking all bindings on keyboard and both Alpha and Bravo units to see if there is any conflict there as well.
I just had a recent issue trying to start the Diamond DA62. Ended up being a rogue fuel valve binding on the Bravo which conflicted with everything despite the fuel valve being moved to the correct position within the sim.
Happy days!