I have a 2013 Winnebago One 29L trailer. It is not qiute two years old. I have been noticing that the tires on the drivers side is wearing too much for their age. I just put on a new tire less than 30...
First thing I would do is get a quality alignment job. Not one from an RV dealer. Not one with a "Correct Track" kit which can only adjust tracking, but a real alignment where they can check and adjust Toe, Camber and Tracking. Axles could both be bent on the same side from hitting a curb, pothole etc. A good heavy duty truck/trailer suspension shop has the equipment and knowledge to do this. I bet that's where your problem is....