Same problem with my Vail Sport tires on my 272QB
I took my trailer back to the dealer. This was one of many issues.
The dealer sent the entire trailer back to Forest River to do the warranty work.
I told them that the tires had to be replaced and the axles checked for alignement and damage.
Here is what FR did. The first thing was they checked the camber on the frame, and found out the frame was not cambered enough. They sent it over to Lippert to have the frame "re cambered". Then, once it was returned to FR, they replaced the entire suspension system from the springs to the axles, although they said they could not detect a specific issue with the axles. Finally they replaced the bias ply tires with Radial tires. All of these things were done as Warranty work, and there was never so much as a question on their part that it would be taken care of. And trust me, I was ready to fight if needed. I don't have the trailer back yet, so I cannot judge how well the repairs were made. But I was very happy with their proactive approach (and surprised based on some other people's experiences) in resolving the issues.
I recommend you go back to your dealer, tell them that you have examples (mine) of where the frame is a contributing factor, and that the camber needs to be checked, the axles and their alignment need to be inspected and possibly replaced, and the tires need to be upgraded to radial tires.
Hope that helps