On our old motorhome I had a couple of snaps that were screwed into the wall which held the straps for the front privacy curtain, the bracket for the fire extinguisher where installed the same way. They were fastened into the wall with drywall anchors. Problem is that the thin flimsy inner wall board and the foam inside the wall just doesn't give much to fasten anything to on an RV.
What I did was to remove the screws/drywall anchors (which wasn't hard as they came out together) then filled the hole with Gorilla Glue and re-inserted the drywall anchors and tightened down the screws. Wait for 24 hours for the glue to dry. The Gorilla Glue is really tough stuff and it solved the problem of the snaps always pulling out of the wall when we used them.