I experienced the same thing with my 2017 2500 pulling a 36 foot 5th wheel one 1400 mile trip and I traded it in. All previous trucks before this hand leaf springs but not the 2500 the Ford 1/2 no problem. the Chevy 2500 no problem so I traded it in for a 1 ton DRW and of course it went away. 4 years no longer have a 5th wheel just a 30 foot cabin boat traded that one in for a 2020 2500 Limited with air suspension with no issue either. That trip this used truck had major electrical and mechanical issues. Traded it in with limited trucks available to a 2022 2500 Laramie with coils and it was back. The coils might be the problem I'm sure I'll hear its not. The coils are set to the center of the truck giving it less stability even the Ram air suspension is on the frame. Solved the problem by adding air springs under the frame.On a 2020 Ram 2500 hemi with the stock suspension what’s the best way to soften the side to side rocking at low speeds? The options I have though of are and I think are in order of whi to try first:
1. Disconnect front sway bar (longterm = #2)
2. Thuren sway bar
3. Different shocks
4. Different springs