Cummins ISX15 No Boost At Intake

Completed an inframe on an ISX15 in a 2014 Peterbilt 367. The VGT was seized on the old turbo so we replaced it and used the original actuator. Truck runs good but has no boost in the intake at 1300rpm. Checked for positive pressure through a port on the intake. Compared with another truck with same engine and another truck with an X15. Both had good pressure out the port at around 1300, blew my finger off the hole. Suspected actuator so I replaced with a spare we had from a seized motor, no change. Swapped from a good running truck, no change. Each time it comes off, I initialize and recalibrate it. Completed hysteresis test (key on, engine off), and it passed. Suspected clogged CAC so we ran a hose directly from the turbo tubes directly to the intake tube. No change. Checked the EGP tube, no clogged. Replaced EBP sensor. No change. Replaced oring and 90 degree elbow for air compressor, no change. No fault codes. Clean air act omitted. Just seems like the ECM isn't commanding the actuator during RPMs above idle. Any advice at this point would certainly be appreciated before I send a road flare into the fuel tank.