#1: If all 4 tires are same diameter it’s not an issue, as has already been said.
#2: If you just want to fix the issue and stop wasting your time with the dealer, change the fluid on the transfer case. Those auto 4wd transfer cases are very particular about having fresh fluid. I have to change the one on the Expedition every 20k or so or it starts clunking on accelleration. Change the fluid and it’s as smooth as can be for another 20k.
It’s like $10 in fluid and 30 minutes of your time. I don’t know what your time is worth but mine is worth enough that I don’t like wasting it fighting with some asshole stealership.