2017 RAM 2500 persistent steering issue

I recently bought a lightly used (< 25000 miles) 2017 2500 Cummings Laramie. When I test drove the truck I noticed a little bump steering, but thought an alignment would solve the problem, I bought the truck an immediately did a 350 mile road trip. The tires were way out of balance, the bump steering was still there, and I noticed that the steering, in a turn, was like driving on patchy ice. When I purchased the truck it had new Ironman Country AT tires. WRONG! If they had been LT275/70/18’s that would be OK, but they were 265/70/18. The wrong tire for a 2500. Long story short, we had the truck aligned twice and balanced. The band-aids didn’t work. Finally the dealership replaced the tires. Now with the proper tire (Nitto) the balance problems and bump steering is gone, but the steering problem still exists, but maybe a little worse. Anyone have any ideas?