Hi, just a quick update @Maarten: polyAT only seems to be transmitted when using midi output A in channel 1. I tested some other channel numbers and then you’re right, polyAT messages stop being transmitted. I have not tested all combinations (including B1, C1, D1), so my report might be limited, but surely polyAT works on midi output A with channel 1. @Thibault_Squarp if you are not aware of that I can test all combinations and make a proper bug report.