Right got a weird problem.

My car should hold 22psi....Obviously you don't normally get full boost in 1st and 2nd due to there not been enough load...In 3rd and 4th it hits 22psi then drops to as low as 16-17 but in 5th it hits and holds 22? My actuator is wound in so much tht some of the shaft has been cut off.
Turbo is a stage 3 (.48) and seems in perfect woking order and to my knoledge there are no air leaks..

Any ideas???