I updated my laptop to latest cumulative update (KB5079473) recently only to discover that Synth is no longer detected as MIDI device. I suspected USB cable, or laptop itself, but after uninstalling this update Synth is usable again, so no doubt it’s the cause.
Found that MS introduces a lot of changes to MIDI support with this update (for the better, it seems, and it’s no joke), but ditches legacy drivers that apparently Synth is using. (Yeah, no other synths of mine has been affected).
Support ticket submitted, hoping that Polyend team will quickly sort these things out.
Ok, after spending some time on investigating the issue, I found a workaround that makes the Synth operational again without having to uninstall KB5079473 cumulative update: after turning Synth on, go to device manager and open it at “Sound, video and game controllers” branch. There, in driver section, click “Restore previous driver”. Once done, shut Synth down and start it up again - you should now find it usable again.