I know this is an older post, but if anyone else is reading it for solutions my first suggestion would be to check the tongue weight. 12% of the trailers total weight should be on the tongue for best towing experience. Sway not induced by wind or a passing semi usually points to light tongue weight. Move some heavier items fore of the axle.
2015 Coachmen Freedom Express 292BHDS Blue Ox WDH
2015 RAM 1500 4X2 CrewCab, 5'7'' bed, 3.93 gears, 5.7L 8-speed VVT, Payload 1608, Max tow 10,400