My 5th wheel is delaminating

[Campingnownthen]

Hey all, our 5th wheel has a pretty large area on the back of the rig that is delamming. Recently had all seams from top to bottom re-sealed but don't know what to do with this problem. I can't be the 1st person to have this issue. Sales people say I need to trade it immediately so I don't get 'stuck' with it. I'm not ready for a different one quite yet. So what do I do? Who do I call? Can I fix it myself? Is it even fixable??

Thanks in advance!