You don't mention the brand. When most claim "Azdel" what they don't bother to mention is where they used Azdel. Hardly any use it everywhere. It's a lot of marketing hype. You also said "rear wall". On a lot of trailers the rear wall is not a laminated assembly like the sidewalls but simply a layer of filon hung on a substrate. You can go on dealer lots and if you look at a slight angle you'll see the waves in the rear wall which is how it left the factory.
Now if you're talking about the rear area of the sidewall, look inside in that area for a cabinet cleat or something else mounted in that location. They often use to long of a screw and it pushes the assembly apart, if it doesn't come all the way through.
If it is delam on a new rig the only true fix is having it returned to the factory for wall replacement. Anything else is a band aid fix and I for one would not accept it on a new rig.
