I'm having an issue with the throttle body on my MK5 R.
UM 550 and stage 1 DSG software.
Car was recently built with pistons and rods.

The problem I'm having, on the highway above 2500 rpm, my throttle body only opens between 33%-40% according to my p3 gauge. Very little boost when this happens. If I let it drop below 2500, it'll open to 100%. Wiring to my throttle body has been checked and some repaired ( had some broken insulation). Ran VCDS, no engine codes or throttle body faults. Ran adaptation and it comes back ok, only thing out of range is step count, its at 11 and the range only goes to 8. Not sure where else to look. Please help.
Thanks in advance.