I agree, that looks like a sloppy fix, contacting FR is the way to go. The roof membrane is pulling away on the seam and there is no amount of dicor keeping that together, eternabond might. The dealer should have addressed this when they worked on the front cap. What worries me is what's under the roof membrane, how long has it been leaking, what's the condition of the plywood and how much water damage is in the ceiling.
2018 RAM 5500 Laramie CC
Sold: Riverstone Legacy 38RE, 960 Watt Solar, 6x6 Volt AGM Battery Bank, Freedom SW 3012 Inv/Charger