scoooby slayer

iTrader: (4)

hi my saphs boost spikes at 25 psi then drops to 22 psi then does a 2 or 3 jumps up and down between 22 and 25 all within a couple of seconds then settles at 22 and holds right up to rev limiter. its a brand new t3/t4 turbo, brand new wastegate housing, brand new actuator with bracket made so actuator is dead square to wastegate arm.
fluctuations were much worse than this before i made new actuator mounting. was tailing to 17 psi previously.
ive removed amal valve and fitted bleed valve made no difference.
i know if probably wont hurt anything its just ive never had one do this before they normally spike then settle to set boost and stay there.
anyone had this happen to them before ?
it bugs me when somethings happening and i dont understand it