No power in low revs

You need it scanned.

I have had it plugged up and there is no faults coming up and no lights on dash
I've also had a smoke test done on boost system no leaks found also someone has looked at the turbo and actuators they are moving fine ??????

Not code read,
Scanned for live data,
Specifically the turbo pressure sensor.
It can read just fine within the ECU parameters so no fault code but could be reading lazy.
Or it could be something else.
Find a tech who knows how to read and understand live data readings.
Not somebody who has a code reader.

Oh and it might help if we knew if it runs Bosch or Siemens fuel system.

I've been told it's Bosch