Well unfortunately I have the known “chuggling” issue on my 2019 L5P Duramax. The issue has occurred half a dozen times and the truck only has 1,800 miles on it. It always happens in 3rd or 4th gear under light acceleration. It feels like the engine loses fuel for a second causing deceleration, then gets fuel for a second and accelerates, the loses fuel again and repeats this half a dozen times before it goes back to normal slow acceleration. For all I know it could be transmission related vs motor related. No dash indicator lights come on when this occurs. Local Chevy dealer is no help. Dealer service personnel told me if no dash light indicator lights come, no code is thrown, and there is no service recall / bulletin on file (they checked and no 2019 service bulletins) ... then I should call the GM Customer Service 1-800 number and log a complaint. Did this today, they logged the complaint, gave me a case number, and told me a senior advisor would contact me in 2 to 3 business days. Should be interesting to see what they say. Will update this post after they contact me.