2012 GMC tranny issues

Thanks for the responses. I did a search and didn't find my issue, mostly hard shifting and slipping and such. I always use the tow/haul when trailing. My mileage is 35400 miles and I will make sure it is documented. I figured if it was some kind of computer problem, they would say it wouldn't be power train. The temperature idea is really interesting. I don't think I ever looked at it when starting. A lot of things get warmer after turning off the engine, maybe sending a message to computer to keep higher rpms? Have to get dw to get the video.