The trigger, Couple At Trackmark, is not allowing the train it is associated with to couple to the car in proximity to the trigger. I have tried moving the trigger but the best I can get is the coupling engine will Begin to move before the "triggering" arrives. Only the trigger should cause the movement.
There are no instructions attached to the trigger so all the above is a guess.
There are no instructions attached to the trigger so all the above is a guess.