I haven’t experienced anything that I would consider a bug that interferes with my music making. Occasional midi weirdness as mentioned above, but nothing I don’t get from from my Digitakt where it also can sort of become unresponsive after being connected to other hardware. A quick un/replug of the USB and its back to the races.
This is very infrequent, weeks go by using it every day without issues, and I believe those issues have more to do with having my DKeys as part of a system. It’s not anything that ever interferes with making music at home. I don’t play live shows like I have in the past.
I cherish my DKeys as a Midi controller/sequencer for other equipment along with its own sound capabilities. I can point out a half dozen other nice pieces in my bedroom studio I’d get rid of long before my DKeys. Never is my timetable for getting rid of it.
One thing to remember when only having 37 keys is that the Digitone buttons can be set to various octaves independent from the piano keys, so I’ll often do simple chords with my left hand on the buttons in a lower octave while noodling the piano keys in higher octaves with my right.