I have yet to see any video evidence of satellites slowing down and/or changing direction. What I have seen is a compelling visual illusion with multiple satellites crossing roughly the same area, fading in and out, which gives the impression that it is one UFO going backwards and forwards. Careful inspection reveals that this is not the case.
Imagine you are watching a road at night from a distance and you see lights crossing your field of view and disappearing, followed by more lights doing the same thing, maybe even coming from the opposite direction. Which is most likely: multiple cars driving in straight lines at constant speed or a single car rushing backwards and forwards at accelerations likely to kill the occupants...?