[Canonman]

Your 32RLI is longer than our Cougar 5th wheel and we find a noticeable difference in the outflow from the ducts closer to the furnace than those at the end of the run in the bedroom. The smallish furnace fans in RVs don't produce a huge CFM number. Plus, there is no real distribution plenum, at least on our model, to evenly send supply air throughout the system.
That said it would not hurt to look at the duct work (if you can see it) for any crushing or deformity. After all it's just an aluminum foil tube. Also check as best you can for any construction debris that may obstruct the duct work.
You can replace the factory floor registers with the adjustable louver types and force more air downstream to your bedroom by closing the living room vents during the night then open them during the day when heat is needed in the living area.