I have a 2019 Equinox Premier AWD with the 2.0L Engine and 9 speed transmission. At around 67,000 miles, the transmission started shuddering as it was shifting through 3-5th gears. Took it to the dealership where vehicle was purchased, and they diagnosed a bad transmission. Paid a lot of money to have it replaced. Picked up vehicle and within 100 miles, this transmission is doing the same thing. There are no engine codes showing and the text stated there were no codes showing for tranny either. At normal speeds, everything is smooth. What are some other possibilities? I am very frustrated at this time. Also, all services are up to date including new spark plugs to rule that out.