UPDATE: Purchased brand new TT and it has leaks

As was said if that TT sat on their lot for months or in some cases even a year and was never moved there is a good chance the caulking got dried out and when you moved it cracked and started leaking. Although it does sound like major leaking??? Also depends on the tilt of the trailer, maybe when you parked it was tilted in the direction letting water run down that side. So to answer one of your question, no it is not that uncommon. Good that they are fixing it though.