The stripping was just a guess, as I couldnt imagine anything else failing so quickly. I just opened it up, the gears actually look fine to me, but its really hard to see :
(full res: https://i.imgur.com/spCwTrC.jpg )
Id show you how it sounds and works now, but taking it apart, I seem to have killed it :). It just sounded "rough" and would skip real bad.
As for the speed, when Im zeroing deliberately, Im doing it roughly at half speed. But I must have done it at full speed quite often too by accident when Im overshooting my target and hitting the edges.