We've had a pesky leak too. I seem to have gotten it stopped. On the back wall (entertainment center) we had water dribbling through the elec outlet and around the window.
I suspected the window but now think it was through the edge trim along the roof or wall joints.
From the volume of water I was looking for a huge gash maybe with a funnel involved. The dealer did some work but did not get the leak stopped, only reduced. I've attacked it by eternabond bonding the roof perimeter and caulking all other trim areas. Haven't had a HARD rain since but during the rains we have had its remained dry.
We will visit the dealer in Sept to have the ent center counter tops replaced. The press-board cabinetry is like a sponge/popcorn. It absorbs any water it can and explodes.
The bad/good news is the dealer couldn't get it done but I seem to have it under control. The damaged counter tops are covered under warranty.
Not impressed with the dealer but it is what it is and we cope. The flip side, I feel Jayco has stepped up and am pleased.
If you find a dealer that, after the sale, has "the 2 C's" (capability and cares), latch onto them!
So, back to your story, keep an eye on the woodwork to catch swelling. Outside of that I doubt that you will have any lasting problems.
Good luck! And post how this spins out.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks