unfortunately some units in the earliest batch had bad encoders soldered on. i’ve been replacing them by hand when issues show up. this is a maybe-fail over time, so there’s a pretty strong chance that even though i fixed one of your encoders, another failed. i’m happy to get the unit fixed (at my expense) and apologize for the trouble. e-mail email@example.com
the currently released update also has not-great acceleration code, which is fixed in the upcoming update, so generally everything will feel better. but this will not fix a sad encoder.
little test script forthcoming to help you identify a defect.