Well, I spoke to one of our hardware engineers about your problem, and unfortunately, it's not clear what the problem could be without actually seeing your H9. The problem that you're describing is not one that we can remember coming up before in that past. The H9 has two boards internally that are connected with a ribbon cable. It's possible that the ribbon cable isn't seated well, and opening it up and pressing on the ribbon cable connections might fix the problem. But that's just a guess at what the problem might be.
If it's essential to get this working for your upcoming gig, have you tried whether the aux switch jack or MIDI are working? Maybe, you could use a 3 button aux switch or MIDI to control the H9 instead? Or since you can use H9 Control with it, could you control it with an iOS device instead?
