I will update the AirTurn library to the latest version and we can see if that somehow helps with the issues you are seeing, as I'm not sure what else to try. As it stands, I've tested a Cicada PageFilp, Coda Music Pedal, AirTurn Ped Pro, AirTurn BT-106 QUAD, AirTurn DUO 500, and AirTurn Digit III, and they all work without issue on both my iPad Pro and my smaller iPad. I don't have an iPad Air to test with, but I don't think that should make a difference.
Mike
Mike