I assume you have a piece of vinyl trim inside your metal trim piece. If you remove the vinyl you will see all the screws that secure the metal trim to the bottom of the bunk board and front wall. It's quite possible, seeing that gap, where the trim piece and sealant have parted, that water has got in there and caused the screws to rust out and loose their holding power, as well as causing the bunk board to rot. Any soft spots inside, on the bunk board ?
2014 Itasca Spirit 31K