Exterior trim and compartment question

[Ragtimeplayer]

I think I saw this referenced in another thread but could not find it. My 2017 2401R MBS with bunk over cab has plastic corner trim pulling away above driver and passenger door in the corner. It is painted. Is there a fix for this? What do others do? Also have a small 5”x5” compartment door above my gray/black tank drain access directly in front of driver side rear wheel opening. It doesn’t seem to open. Anybody know what it is? Is it an access to the slide out linkage or ??