Cracks in Paint Around Awning Mounts

The awning on our Sportsmobile (2004 Ford) shakes when driving on bumpy (washboard) roads, and after two years of use, I've now noticed that cracks have appeared in the body panel paint around where the awning attaches to the van. There are 3 thick cracks, each almost an inch long, around both of the rear awning mounting brackets. Some of the cracks are deep, but I can't tell if the bare metal is being exposed.

I've been trying to talk with Sportsmobile about this issue, but they don't have much experience with it.

The awning is hung from the rain gutter in three places, and bolted to the Sportsmobile down below. The rear two sets of bolts seem to be only attached to the surface sheet metal, which flexes quite a bit when the awning shakes. The bolts are tight.

Here are some photos and a video showing the body panel flex.

More info about our Sportsmobile is here...