POLAR
Do you think its leaning because you can “see” it leaning or because of the uneven tire wear? If it is the latter- once a tire starts to wear badly there is no stopping it. I had similar issue and when I switched from bias-ply to radials it stopped. However, I also had a small bent axle issue- you can get them straightened sometimes without having to replace them. If your weight -distribution hitch is out of alignment on the brackets on the trailer you can get an uneven distribution of weight back onto your trailer causing one side to be weighted more than the other and , thus, more downward force on one tire than the other-thus different wear patterns.
Rick