I do not know whether this belongs in the Cubase category, or the Dorico category, or the Pianoteq forum. But I shall start here.
Using Pianoteq 9 Std, if find almost no difference between dynamics, and can barely hear pp or lower. Yes, I have played with the power curve setting to no avail, and all the settings i can guess at in Pianoteq (great VST but the manual is very sparse on detail.). And I have played with the Dorico mixer (a common source of posts about low volume).
Yet when I export the MIDI for the piece and run it into Cubase Pro 15 the dynamics are clear and strong, with no FX inserts or any fiddling.