Sounds like the engine is lugging a little maybe… are you at low RPM’s when this happens?
There was a TSB (technical service bulletin) for something like this on the early year KK’s, but I am sure it was sorted by 2012. For the 08/09 years that had this issue, Jeep reflashed the computer to adjust the shift points slightly.
Do you know the last time your transmission had its filter and fluid changed? That might be what I’d try first, if it has never been done. Transmission fluid has friction modifiers that can wear out if the fluid is very old, leading to transmission shudder. Your other option is to try a bottle of “Instant Shudder Fixx” from your local auto parts store. This has eliminated the low RPM shudder in mine, which started over a year ago now. It took like a week to work, so it wasn’t “instant”, but I am happy with it.
You must be registered for see images attach