Got my trailer back from the dealer. I can see what has been done to address my problem (hopefully...). The "bubbles" are so small the fix would likely be worse than the problem so I am going to live with it. Anyone with the same setup might be interested. A little elbow grease and an hour of a person's time my save their trailer from the same fate as mine.
I've attached some pics showing the removed screws (from the bottom only, beside the mounting clips). Apparently the dealership made a dam that goes over the edge of the opening, it is not visible because it would be under the caulking. The outside cover was removed to do the repair, I believe.
I have attached pics of the vent setup. It drains out the fridge vent cover as required. I can't say for sure that it has always been where it is now.
Hopefully this helps someone, see what I mean about the bubbles. You can't even see them in the pics.