delivery can be variable , even on a working properly std car
however only within a relatively small margin (few psi)
dont suppose you put normal unleaded in recently?
anyways, just to be sure , find a local person with VCDS , and get some logging done on boost/fuel etc
That will tell you if its doing what it should
DV , PCV etc can all cause boost issues btw
one of the main reasons I would recomend fitment of a boost gauge works well and continuosly tells you how the cars getting on.