I have this glitch very occasionally. Usually, if I force-quit the scrobbler and music player, reopen both and then search for scrobbles it won't find any, but future plays will then be found. I assume you're using the default Apple music player to listen to your music? If you aren't, maybe that's the problem as the scrobbler uses the play count from your iTunes library info, I believe (though don't quote me on that!).