I would check your roof where the front cap meets the roof for bad sealant. I had a similar issue with our current fiver. I put Eternabond along the entire seam and then found another small leak where the side gutter ends at the front, again use some Eternabond and now all is dry.
My water came on the side under the cap when I would lower the nose. Luckily no water damage has been found. Climb up on the roof and inspect every spot there is sealant.
Good luck.
2008 GMC Sierra 3500 SLT DRW D/A 4x4 (Big All)
2006 Ford F350 PSD SRW King Ranch 4x4 (Henry) (Sold)
B&W Companion, 90 Aux Fuel Tank, Scan Gauge II, Curt f/m hitch, Swagman XC
2015 Forest River Sierra 360 PDEK
DW Diane, DS Michael, FB Draco and Sabian