Tranny hesitating

[Leedall24]

Fairly new here, so this may have been covered already. I just bought a 2018 Silverado with 43k on it. I installed a Range AFM delete, however, when I mash the gas to pass or go up a hill, the truck hesitates, bad. The front of truck feels like its falling foward, like the tranny is confused about what to do. Finally, it takes off, but still feels like its slipping. Only on hard accelleration. Otherwise, during normal driving, it seems ok. Truck has warranty, so I dont want to tune just yet. Also, truck seems to have an occassional hard miss at idle. Any advice would be greatly appreciated. Thanks.

[2018GMC]

Thats NOT normal.

 

Take it in to the dealer.