that's definitely delam.
what year is it? it looks like an older used model and probably no longer under warranty.
and this happens little by little over time.
this had to be happening for some time, to get to the point of its current condition.
did you not inspect the door on a regular basis?
this happens by water intruding into the door frame and hinge area.
this could happen by trapped canvas, torn/compressed seals, water draining from roof or marker lights, warped door.
bottom line is that the bunk door is not safe in its current condition.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC