Mold on dinette frame under cushions

I believe that having so much mold after only being used six times isn't likely due to camper usage. It seems more probable that water seeped in from outside.

Water usually doesn't cause mold unless it stays for a long time or gets repeatedly wet. Even if it was condensation from the heater, which I've never seen, it doesn't add up, especially considering the limited usage by the original owner.

I suspect water might have entered through a window, running behind the walls or elsewhere without leaving visible marks. Water needs to come into contact with wood multiple times or soak in to leave a visible mark.

Again based on my experience, I find it hard to believe that such mold would result from only six uses of the vehicle.

Second thoughts -
COULD it be from the original owner leaving something wet in there (folding kayak, skis, etc)  OR leaving a window open and water getting in that way, or is a cap missing on the roof for the fridge???