"dealers involved say the truck is working as designed."
They always say something like that when they don't have a clue which in my experience is way too often. It is surprising how often I have to do my own research and then educate the dealer. My Ford dealer recently told me that he had never heard of adaptive shock absorbers that are standard on the Fusion Sport. My Kia dealer did not want to sell me updated software for the GPS because it takes too long to install. I found out that I can have it shipped to the house and do it myself in a few minutes. The list goes on and on. The real problem is that most of the time when I call the factory for help they just tell to go back to the dealer that has already demonstrated total ingnorance of the issue.