Wow after reading every ones post and you comments I got nothing. Did hear of a bad shock doing such things on a dodge site but you got blisteens so that's probably not it . I had a similar experience with a new 1500 ram fully equipped for towing and had the same problems as you added air bags, changed wd hitch to a highly recommended model with no improvement. Traded to 3500 cclb 6.7 problem solved. I've concluded I don't think rear coil springs are good for towing. ( my opinion)
I hope you get this solved as I don't think you should have this problem
I wish you luck
