Had the same issue with my…
Had the same issue with my 2013 Suburban. After the dealer flush and 2000 miles, I started getting the torque converter shudder. Mine has the 6 -speed. I went to a reputable transmission shop who ended up rebuilding my transmission and put in a HD torque converter. He told me that these issues are common with all makes and the 6/8/10 speed transmissions. Very disappointed in American engineering. Never, I repeat, never have a transmission flushed. It is just premeditated failure. Drop the pan, drain, and fill, is all that is needed.