Are you positive it was closed tight? I made this mistake once, luckily it didn't rain and I noticed it the next week at my storage facility.
No, not me. It should be easily diagnosed though (if that is the issue) as you can very easily get to that from the roof to check the seal, then of course spray water on it and look for leaks if it isn't obvious before.
"they" say that roof leaks are super common in trailers. Yearly you are supposed to get up there and inspect all the sealant and replace a lot of it as preventative measure -before- a leak occurs too.
TH : 2016 Stealth WA2916
TV : 2012 Ford F-250 PSD