Vancouver Island is a high humidity environment, which I am sure is forming condensation on the aluminum ribs in the roof with drips of water staining your wood battens with the vinyl "photo finish". Our 08 Hawk also has a very low quality vinyl faced plywood everywhere and vinyl-faced finger-jointed battens stapled to the roof ribs. During sub-freezing temps I frequently see frozen droplets on those battens. Our staples have loosened, and I can only tamp them with a finish hammer, but they continue to work loose. Considering the owner of the camper will stare at this workmanship, I would have designed a better product.
I suggest you consider replacing those battens with something inert. Possibly a vinyl trim strip from an automotive / body shop supply.
I would also install with (self-tapping) screws and would never expect a pneumatic staple to perform in a camper designed for Four Wheel adventures. Personally, I find the cabinet/trim package to be substandard, but I've heard they have improved their product.