It is very common on older Freedoms (ours is a 1996 Microlite) for the felt/foam roof lining to sag and detach at the wall edges.
We have support at each side for our lining from the shower room wall on one side and the wardrobe on the other. I reached behind the lining and removed some aged foam which had dried out plus some previous repair tape which somebody had stuck in previously.
I carefully sprayed behind the lining with flooring contact adhesive (Like Evostik) and pulled the felt back into place. Not perfect but an effective repair. A surprisingly easy fix
------------- cramming for my finals in the twilight zone