Repair insulation peeling off at interior roof line

I own a 2014 Fleet which I purchased in 2020 in San Diego and drove across country, arriving in Ann Arbor as COVID shut the country down. LOVE the camper but no dealer close.
Inside insulation is becoming detached at corner.
Also, interior roof needs shoring up.
Any suggestions or reputable service people near SE Michigan???
Thanks

pictures of what your issues are would be wonderful... others might want to see and learn from your experiences and eventual solutions! If you can't figure out how to post pics, our moderators stand by to help you!

The roof consists of the top aluminum skin supported by a ladder style framework of square aluminum tubing. The lengthways framework can be decerned by the trim strips on the interior ceiling. Within the roof ladder open sections is cut to fit panels of foam insulation. These panels are not affixed/glued...if you push lightly you can feel them shift up/down. Thats normal.

The perforated headliner material is just vinyl sheet. If this is just drooping a bit in spots you can try to peel back a section as needed and use a suitable adhesive such as 3M spray 77 to get it back into place. I'd use the adhesive like a contact cement...light coat on both surfaces, wait 3-5 minutes, put back into place.