The most dreaded thing that can happen to an RV because if allowed to go unchecked, it cause devastating damage. mine happened when I hit the brakes in rain, woosh a wall of water came down on top of me. The cause was the front cap separating from the roof because the sheet metal screws had backed out and some were even overtightened and stripped. I purchased some #12 x 3/4 screws to replace the stripped #10’s. I tightened/replaced the loose screws, then used Dicor self leveling sealant to seal all cracks and then to take the belt and suspenders approach, covered both caps front and rear with Eternabond tape, 3 inches wide. I think this one is permanent.
