I guess you have won your bet! That indeed was the problem. This issue is neither addressed in the written tutorial nor in the video. The out of limits problem that can be checked by the "Forcefully connect JW" is something different than the animation not starting, due to the limits being to low. Thank you very much!
However I have also discovered, that you have to add the SAM objects into a scenery-group on WED - otherwise it doesn't work. Might be obvious for those regularly dealing with WED. But just simply dragging it and saving didn't work for me.