We were using a 2017 2500HD Duramax to pull our rig and upgraded to a 2020 3500HD Duramax. When testing the trailer brakes in the driveway by manually using the brake controller the trailer brakes do not lock up and stop the truck. Doing the same process with the 2017 truck it would stop the trailer immediately. I spoke to two GM seasoned mechanics and the 2020 uses a different type of brake controller allowing the truck to calibrate the amount of force the electric brake needs to apply during braking. Just wanted to see if anyone has experienced the same issue and if anyone has any feedback?