Problem - Adjustable Rider Backrest

[LiveToGlide]

I installed the Adjustable Rider Backrest Part #52596-09A. It worked fine for a couple months and all of a sudden this past weekend the shock (not sure proper name) does not have any pressure to it and the back rest just moves front to back without using the push tab hooked to the cable. I noticed this while on a weekend trip and thought maybe the cable came disconnected. I took the seat off tonight and the cable is connected on both ends. You can slide the shock up down by hand.

Any thoughts/suggestions?

Thanks,
Rich