Condensation inside walls.

We have a 2014 Passport Ultra Lite Elite . At the head of the bed, located against front wall is a seam strip 10" above bed base. Our temps are in 30's-40's and the section below seam is wet with condensation . The area above is dry. The outside is seamless fiberglass. Could it be due to omission of insulation in that area ? ....or ?