watch the video in the link. This is what the OP meant by pixie dust. My daughter also noticed it be done less on our last trip Dec 13, it used to happen almost every ride......we usually ride it about 20x per trip.
about 27 seconds in https://www.youtube.com/watch?v=aGJZiha0OvM
about 27 seconds in https://www.youtube.com/watch?v=aGJZiha0OvM