I've had the same problems as well. To me the ability to scrobble properly is the priority #1 of a music player after it actually manages to play the files. Missed tracks, no scrobbling, every other track skips, wrong now playing info. Nothing is working consistently. Official LastFM scrobbler, Scroball, Simple LastFM all fail in a way or another to the point of utter frustration.
However I managed to solve all my problems by reverting back to the V2 legacy version of Poweramp as its not broken when using Simple LastFM scrobbler and I've had zero issues since. Too bad I can't enjoy the pretty new UI but I'll take actual functionality over UI any day of the week.