I assume you are talking about external trim strips and not inside the coach? I had both come up during the current hot spell in southern Ontario (Humidex of 105 deg yesterday).
Interior trim strips between wall panels replaced by dealer.
Exterior trim bulging on the front cap to wall joints on both sides of coach. Dealer tried to reattach with silicon while getting other warranty work done... Bulge reappeared the next day. Dealer tech applied full bead of silicon caulking to the bulge to seal and I will assess what to do this Fall.
2016 F-350 Crew Cab 4x4 Dually Diesel, 2013 38BR Office config with all options and upgrades but Ceiling Fan and Ice Maker.