Roof space boot cover

Hello friends, I have a tricky question, in my boot space I have the plastic cover for the roof to drop into, there is a plastic bar at the front which you fold one way to lift the cover and fold the other way to drop the cover, now the problem with mine it doesn’t matter which way I move the bar the roof space cover remains down, it’s if a spring or band has come lose or snapped, is there an easy fix for this as at the moment if I need more boot space in the winter I need to hold it up with a made up box, hope this makes sense and hope someone can help, thank you……