recently my M9 having this issue, when I step on the top centre switch B2 it automaticaly activate the tuner despite i didn't press the B3 switch. It affect me during gig as I need to reconfigure my set up and I only have to use row A. Even the row A having intermitternt issue that when I press A2, switch A3 also follow.
what might be the issue? I already done the update, re-flash the firmware even change new adapter. is it the circuit board or some other issue?