mzak is dead on with how to fix/tighten the corner molding. Depending on the condition of the wood below the trim, you may have to slip in a wooden matchstick or some wooden toothpicks with some wood glue on them. Clean off the old caulking and re-caulk the edges of the trim. I noticed this happening last year, then while at a FROG rally in Williston, FL. the service speakers came around to our sites and allowed us to ask questions about repairs that we felt needed to be done. The advisors then gave us hints on how to go about doing the repairs. What a great benefit we received while at the rally.
2017 Ram 2500 CTD CC SB 4x4