Low end travel trailers typically come with poor frame paint and under carriage plated hardware. As you can see just one or two years can lead to corrosion. A few more years and the corrosion can become significant.
I painted all the underside plated hardware because the cheap plating typically rust in a couple of years. I also painted all the visible parts of the frame for the same reasons. If I had more ambition I would have painted the entire under carriage.
Get the dealer to have the entire under carriage repainted using good quality paint. It is a lot easier than doing it yourself.
Waiting a few years to repaint is even worse. Corrosion removal without production quality equipment is painfully difficult.
Kodiak Cub 176RD
Nissan Pathfinder 2015