Cummins 605/2050 immediate RPM drop issue

[WICT800]

Hello I’m new here and my company recently let me spec a new T800 with a Cummins 605/2050 CM2450 engine 18 speed, now the issue I am having is in between shifts or even just revving the truck at a stand still the rpms will immediately drop off and the air throttle actuator will close, my local Cummins dealer seems to think this is “normal” but after speaking with many others it’s in fact not normal at all which is pretty obvious to me. I was recently told there is a perameter that can be changed on Cummins insight that will solve this issue but I was not told what exactly to look for, any help is greatly appreciated