hmm, the fact the UM-ONE is showing as two usb devices (ports in usb terms) could be the issue - it may be the MM is connecting to the first it sees, which might be the output.
@danngreen would have to confirm that.
unfortunately, I suspect the only way forward on that is for the MM to allow device selection in the case where it sees multiple.
(this would be useful for other devices too)
have a look thru the working midi devices topic , theres some options there…
personally, I know the Blokas Midihub work… and is a nice bit of kit - though goes beyond being just converter.
oh, I thought it was usb class compliant… but don’t know for sure.
(ofc, as above, even if compliant there still might be something else going on)
btw: @danngreen , it would be very useful if the MM displayed a quick popup with full device name when it sees a device connected… or perhaps in info menu?
this would us know if devices were enumerating correctly… and also if its just picking up an unexpected ‘port’.
perhaps if its in the menu, then that means later, it can be ‘extended’ to allow an alternative selection (when multiple are available)