GMCDenaliLife

I stumped everyone here

Hi All, First time poster so I apologize if this isn’t the right spot of this question. I have a 2020 Sierra 1500 with just over 27,000 miles and in the last 6-8 months every time I decelerate (coast and brake) between 15 and 30 miles I hear a audible but not enough to get on a recording grinding/rubbing noise below me. If I touch the accelerator pedal ever so slightly it goes away and you don’t hear it with highway speeds. Once I go below 14 mph it goes away. If I put the truck in neutral it also goes away or isn’t there. It also happens in 4 wheel drive. I have taken it to a mechanic and they hear nothing and everything checks out. But, this is very audible and happens every time I drive. Any thoughts? Things I’ve researched heavily leans towards transfer case issues. Also heard about U joints, CV joints, wheel bearings (shouldn’t be the cause due to the neutral test), and pinion issues.