I experienced the same problem with my brand new 2013 Whitehawk DSBH. We took it on a few short distance trips after we got it to break it in. Then we took it in September from Orlando to the Smokey Mountains. Before we started home I noticed the inside of one tire was extremely worn. All the tread was gone. I put on a spare and made it home. We took it to our dealer Orlando RV. They said they found nothing wrong and put a new tire on it. I don't believe they even tried to trouble shoot the problem. I feel this way because the outdoor speakers were intermittent and they told me there was nothing wrong with them either. I went to pick up the camper, tapped on the speakers (like I told them to do) and they immediately stopped working. I am going to do the same trip this fall and I am concerned I will have the same problem. I am sorry I can't give you an answer, but I am hoping your dealer is more thorough and will give you a better solution than slapping a new tire on it. If you find out more let me know.
2012 F-150 Lariat, Ecoboost, 3.73, Max Tow Pkg
2013 White Hawk DSBH
Equalizer Brand 10,000 lb. WD Hitch