I would verify the tongue weight of the camper is up in the 12 to 13% or higher per the GVW of the camper.
And, if you changed trucks, did you totally reset the WD hitch for proper weight distribution (WD) on the truck and then adjust the hitch up and down to level out the camper?
If the WD is all wrong and the camper is nose high, it can affect the towing. Depending on the actual camper, some lose tongue weight when a lot of nose high. And on some, nose high can create wind currents at the top front of the camper that can cause unstable towing.
Hope this helps
John