I had the same clunk noise in my Platinum, From Day 1, took i to the dealer, they re-torque the u-bolts and everything in the rear end. No solution. They told be there is a Recall for this. And that they change some parts. 10 month waiting and no news of the parts Yet.
But, in the meanwhile, I...
Ughh, I have a Platinum and I was thinking of swaping the wheel (did it in previus 16 Lariat, and worked great). Did you have any Error Message or just adaptive steering not working ?. Thanks and Best Regards.