I have a 2017 Suburban with the 5.3L and have been having the same hesitation and stuttering up hills or under constant load described in this post. I thought it might be the AFM system so I purchased an S1000 AFM disabler from Diablo sports. It is easy to install, you just plug it into the OBDII port and you are good to go. Since installing it my problems have gone away. I was originally skeptical that it would help but having read this post and a few others I was at a loss and did not really like driving the vehicle so I figured it was worth the $200 to try it. It now drives like it should and is way more responsive accelerating after a brief time of light load operation.