I just signed up to report exactly the same issues as above. I’ve only had mine a few days, and pretty disappointed, still considering a refund but I wish this wasn’t the case, as the Hermod covers a lot of features that are important to me.
I’ve been experiencing stuck gates (occasionally), hanging notes (very often) and also unstable pitches (occasionally).
In my case though, I think it’s mostly been while using my Arturia Keystep (via the USB in) when these issues have happened. Except for a couple of cases of the stuck gate, which just happened randomly IIRC.