Welcome to iRV2 .
Sorry your first post is about a problem .
The tread wear you describe , is classic bent axle , most likely excess camber ; toe out would feather the tread all the way to the outer edge.
Tire overload produces a different pattern .
Axle mounted off line should produce wear on the outside of the tire on the other end of the axle .
Having already replaced axles; and having the same issue repeat; makes your issue a mystery
Without being set up on alignment equipment , any GUESS as to the actual cause is just that , a guess .