SetPositionTarget Stops working when model stops moving

Hi ,
I’m using UPhysicsConstraintComponent SetPositionTarget, and it works as far as the model is moving. When it stops moving it just then stops working. At the start because of the spawning oscillations in the model it moves without any problem but when it stops, if a new TargetPosition is set, it doesn’t move.

Why is that? I’ve seen that depending on the Physics sub-steps set and whether or not you use sub-stepping, it happens less often.

Does anybody know why this is and is there a way of guaranteeing that the joints work always?