If it is delamination, that is a major problem. From what I've read, there is just not a perfect solution to fixing it; it can cost a lot of money. I ran across
this thread on another forum that discusses the isssue, along with some repair suggestions. Sadly, I agree with clutch that Jayco is unlikely to do anything to help, although you checked your roof and made repairs as needed; it is, after all, their design that is leaking. Good luck, and let us know what happens.
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There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2021 Chevy Duramax; Pullrite Superglide Hitch