Please follow along with the advice in the other thread, here, about how to double check those mechanical parts, and adjust the current if necessary:
If the tension seems correct, and things seem to slide smoothly by hand, it does seem likely to be a current limit adjustment that is needed. However, the fact that it changes as it moves suggests that there may be too much slack in one or both of the cords; you should double check that the rod ends are square at both ends of travel.
