I would say that's the way it is. I know our 36RL looked that way. The newer units with the cable system is setup a little different with the gaskets and seems to fit much closer to the outside wall. At least that's my experience between our 2012 36RL and our 2016 39MB.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top