It works in one direction, but when I try to switch in the other direction the knob-lever will move, but the track won't switch. I can do it manually by using my finger to move the metal prongs after moving the lever and it will then move back. About 1/4 four times it will switch by moving the little knob-level Any advice on fixing this? WD40? Or would I better off buying a new switch. It was brand new.