What is puzzling, 6 year old tire/rim setup. Did they run out fine until recently? In many years, many vechiles and many sets of tires, I’ve never had a tire just go bad or lop sided after however long….
Except for 1 Firestone Destination MT, maybe coincidentally. And it wasn’t bouncing or “out of balance”.
It caused the truck to pull to one side. Ruled out alignment. Swapped front tires back to the rear axle. Problem solved. Rotated back to the front again later and no more issue. Dunno if it slipped a belt and then corrected itself or what , but tires don’t just go out of balance sitting there.
Something to think about?
And it’s even more unlikely that the issue is the rims.