My 2019 started the shudder at 900 miles. Since Dec. 28th it's been in the shop twice for a total of 27 days. First time they did a flush and it started shuddering again after 200 miles. Next trip in they said they couldn't duplicate the shudder. Also said GM just came out with a new service bulletin (February 2019) and they aren't replacing torque converter's anymore, just some kind of new fluid change. They didn't do that to mine as they couldn't duplicate the problem. Now have almost 4,000 miles on the truck and yesterday I backed out of the driveway, put it in drive and 1st gear was pretty long and when it shifted to 2nd it slammed REALLY hard. Mine will slightly shudder while accelerating from a stop as well as going up a grade. Very noticeable between 45 & 55 mph. Two times now the radio display will start vibrating wildly and will change stations by itself and mark each one as a favorite and locks up all controls. I've kept in constant contact with a GM senior customer service agent who assures me they will fix the truck. No they won't. GM turned me over to a senior agent after I asked them to either give me a different truck or my money back. Has anyone out there had better luck getting this 8 speed tranny actually fixed and if so, how was it done? I'm about done with this.