2021 2500 sounds like it has an exhaust leak, it sort of rumbles, that way. It still makes 25ish psi boost so, it ain’t leaking terribly. Recently had a recall done and the body shop had to keep it a week because one of the service writers hit my truck in the dealer lot. Where are most leak prone spots?

 

I'd take some soapy water, and spray the exaust system. (when the engine is cold or right after start up) and if you dont find it, at least you cleaned your exaust.

 

Get a buddy, wife, kid or whatever and take then out to the truck. Let it idle while you plug the exhaust with your hand, a large potato, a board or something else similar. While you have the exhaust plugged, have them check all over the truck for the sound of an air leak. Very easy find the location of exhaust leaks this way.