Just because something is new, does not mean that it was built right.
I have had four 5th wheels, and everyone of them has had leak problems, and two were new units.
If you saw the way that RV's are make, you would be amazed that there are not more problems. On my current trailer, that I bought used, had two major problems. There was about a 6 foot section of wall that was not attached to floor plate, and it had opened up about 1/4" and you could see the ground through the crack. At the front connection between roof and siding. Installation was very poor. Instead of batten strip attached to structural member, it was just screwed into 1/4" wood deck, so screws had not holding power. Major leak developed over time, that requited rebuilding of front wall, section of side walls, and roof to correct.
