2350 differential pressure severe

[Cummins92]

Hey guys new to forum. I own 2 matching 2016 western star 4900 trucks with 2350 motors, the one I just got has a code for dpf differential pressure severe level. Stop engine light was on, we reset after treatment maintenance, and did a manual regen but it would never get up to temperature.
Limited info I know, but I will spend Saturday trouble shooting if anyone could help where to start . The actuator on the turbo is moving freely. But I do know before I purchased truck the turbo was swapped off of another truck. ( vgt calibration needed maybe ?)

My other truck as soon as you start it you can hear the turbo spool up but this one you can not hear that. Idk if that’s a indication of anything. Thanks for the help in advanced. I would also like to look into demandating both trucks as well. But getting it running right first would be nice.