Dometic Oasis over the door awning - One arm is not springy

Mine is exactly like that. It is the left side as you are facing the fifth wheel. Been that way for years. i just unroll a little, then reach out the door and give the stuck arm a yank and it pops right out. The cause is some sort of binding in the fold up mechanism, I just have never fiddled with a fix if there is one. My money is that the spring/shock is not your problem.