Out of Vehicle Engine Dyno test failed to reach Factory Torque Specs

I have a 2019 L96 (RPO) 6.0L Chevrolet Engine that is being Engine Dyno Tested and not a Chassis Dyno. The torque on this engine is much lower than factory rated Torque Specs. I think it may be the ECM believes the vehicle to be in Park or Neutral and has limited torque limits. Does anybody know what settings needs to be changed to allow the engine to produce maximum torque without changing any factory emission settings? Also, what does ECM 12838 Tip in Limited Mapped Gear Numbers mean?
Any help from the tuners would be appreciated, if they have dyno tested under these conditions before?