Second time out in our 2014 sierra 376BHOK. It was in the 50'sthe first night & we didn't turn the heat on until morning. A few hours later a band of condensation formed around the inside frame of the bunks & was actually dripping on sides & about 1" at top. The next night chilly but we ran heat all night & no condensation. Had camping world look at the side & they said it was sealed well on slide. What the heck happened.