different than expected my mc does not recognize trx-b2 and especially GND-SN machine as melody-machines on my md. So i'm not able to use arp, mdnotes and euclid, melody helper with these machines. I'm on a MD MK2 (no UW) with the actual Elektron FW (1.53c) Other machines work well as melody-machine.
are you using the firmware that came with the MiniCommand? That's still an "old" firmware, because it fits the manual. In the patch manager, the new notes and melody firmwares are able to work with GND-SN and E12-BD and a whole lot of other machines.