I think what Kazzie means when she is talking about the stand 32 airbridge is it's tendancy to roll backwards. It's very annoying when you put it on an aircraft and let go of the controls because it will roll back about a foot leaving an unacceptable gap between the platform and the aircraft. What you have to do is come on almost parallel to the aircraft, that way when it rolls back it doesn't roll away from the aircraft just parallel to the skin.
That is terrible if a gap was left big enough for someone to fall down, even a kid. The jerking you experienced might well have been the autolevel tracking the aircraft as it is loaded. That is quite normal and is what stops the bridge taking your door off!