Not making full power

Did a conditional on a Bristell with a 915.  A few flights later, WOT wouldn't go above 4600 RPM.

Connected BUDS and downloaded the logs, sent to Motive for review, nothing peculiar to report back.

Found a hole in the fresh air scat tube to the turbo, replaced with new.

Did another runup, still 4600 RPM.

Rechecked scat tube connections - all good.

Checked throttle  - no binding and has full throw

Checked all air connections to turbo and throttle body - no defects and hose clamps tight

Borescoped exhaust - no blockage

Checked fuel filter - clean and no blockage

Fuel flow and pressure - reported normal by owner

Wastegate - moves freely

Checked low pressure hoses to wastegate actuator & pop off valve - no defects

Checked turbo vanes - no defects and turns freely with no resistance or noise

Propeller - fixed pitch and blades tight

Air filter - no obstructions

Exhaust/turbo mating- all four bolts torqued to 216 in lbs (25 Nm) although there is evidence of a very small exhaust leak on the top

Both the wastegate actuator and pop off valve low pressure lines connect to pneumatic solenoids that I have not found how to test yet.  They are three Kuhnke SP764.0546.

What am I missing?  Any suggestions on what else to look at?