Ford2GMC

Hi all, I’ve searched everywhere to find any similar issues and can’t find anything. I have a crew cab 2021 1500 elevation with the X31 package (5.3 8 sp). 700 miles, lately I feel like there is a vibration under my butt and under my left foot at low speeds and idle. My truck wasn’t equipped with the DFM, and I always shut off the auto start/stop when I get in the truck. I took it to the dealer and explained but they said they can’t find anything wrong. The vibration isn’t crazy, but it’s noticeable in my opinion. Any idea what this could be ? I’ve seen vibration posts be anything from motor mounts to u-joints etc. Am I going crazy? Any insight appreciated.