I had this same problem! My print head was visibly stuttering during perimeters where one perimeter pass would end and the next concentric perimeter pass would start. The issue was my jerk speed was too low. For some reason, M566 in the config.g file for jerk or instantaneous speed change is in units of mm/min rather than mm/sec, so you have to be cognizant of that when you dial in your settings. I just stepped mine up to 2400 mm/min (40 mm/sec) and now my perimeters are printing beauteously, and not leaving an obvious bump where the part's seam is.
I really hope this solves your problem. It solved it for me!