Without pics and more info this is hard to answer. Possible you have a 6 inch lifted truck and the trailer frame is not towed level to pavement? Perhaps this axle is the only one with working brakes? Lots of things to consider.
If it were me - I would be ready to replace tires that were not perfect on my camper so I would drop by the RV dealership on my way to the tire store since I am hitched up and pulling. Just ask the service writer to take a free look and see if he had any ideas. He sees this stuff every day so maybe he can find problem fast and easy by looking at spring hangers and such right in the driveway and not have to leave camper. Then I would be off to the tire store where they also see this stuff every day. By this time you may have an answer and be ready to make repairs as needed.
I guess what I am saying is take your rig to some professionals and see what they think. Maybe you already have some ideas to check-out??
I am still trying to see in my head what "chewed" tires look like?????