Had same problem a year+ ago with my 2018 Chateau F550. First time noticed rain water on the above-the-driver-seat bed.
The vehicle was on the manufacturer warranty still, but the dealer blamed Ford. Although Ford acknowledged the fault, they refused to pay since their 90 day warranty on sealants already expired. Since it was the middle of camping season, I had no time to walk through all these labyrinths of bureaucracy and payed the dealer out of my pocket.
When I inspected the results of "repair", I understood that it would not last long. The dealer just added additional sealant layer on top of the old one.
Few months later I noticed a strange sound from the cab. Here what I found:
Sorry, I can't attach images. Adding Dropbox link does not work either...
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