i've seen a few of the new ones do the exact same thing that usually happens for fuel efficiency, does it get stuck in neutral or as soon as you hit the gas it engages in gear.
As soon as I hit the accelerator it engages again and also the same if I hit the brake. I was driving a 2016 and it didn't do that; is this situation I'm describing an option or is this an issue withvthe transmission?
Eco Roll. Just pull the Jake brake lever toward you one click for setting to "1" which is 30% braking, 2nd is 70% engine braking then you have a 3rd. (The lever over the windshield wiper lever) So you have Off, Auto(Eco+Roll), 1,2,3. "Eco Roll disengages the driveline and lets the truck roll for the optimum period before re-engaging the driveline."
There is an adjustable parameter to turn ON or OFF the Eco Roll feature, by default trucks come from factory with this parameter at ON , the PTT tool is require to make the change. With truck(2013-2014) is was possible to have Eco Roll feature only under cruise control operation not on pedal operation but now you can only turn ON or OFF for both Cruise and pedal. Ben
Note : On Volvo truck with I-Shift version F 2018 and Up the Eco-Roll (I-Roll) can be turn ON or OFF using PTT(VolvoTool) transmission parameter and but the option for Eco-Roll on cruise control only, no more exist from factory. Ben