2017 Ford F350 - Shakes when towing

My truck shakes quite badly at times over 90 km as well as when I am hauling my horse trailer. I have had it to the dealership many times and no one can figure it out. Very disappointed in my dream truck.

A class action law suit has been filed against Ford for this issue.

Tester

Owned it for 4 yrs? Or recently got it? Does not matter how trailer is loaded? Tongue heavy or light?