I have a 2019 with 13k on it now, experienced hard downshift into first gear when braking hard and a not “smooth as butter” shift from 3-4 like all the other gears normally shift. took to dealership they claim normal operation, its a heavy duty tranny so you will feel stuff like that. Ok? So i have a 60k + truck that feels like the tranny is falling out of it. Great! My buddys father has a 02 low mileage single cab and had a few hard shifts occasionally and he said to try driving in tow haul mode once in a while, the trannys are ever learning so from my understanding if you throw different shift points and patterns at it which is what tow haul mode does, it will learn those shifts and forget the bad ones? I have noticed smoother shifts across the board and the hard downshift is gone, even though i get nervous coming to a stop light from 40-60 mph in fear of the infamous boom that is called first gear. Hope this helps, it worked for me!