I have the same problem with my 2019 Laramie. This only occurs when slowing down and under braking. Has been doing it for close to a year. 5.7, 8HP75 Trans, and 3.92 rearend. I have found that if you place the truck in tow/haul mode, this does not happen. Changes the shifting points when the truck is downshifting. However, in tow/haul mode, you lose the "ECO" mode, so get ready for your gas mileage to fall off. However, I would rather be safe and pay a little more for fuel than getting rear-ended because the truck failed to operate as intended. I am outside of my warranty, so waiting for FCA to come up with a fix before I go down the road of repairs/replacements, as otherwise, it will come out of my pocket.
@RamCares