I had a very similar sounding issue while using ASXP and what resolved it for me was disabling "Use Global Static depiction mode" and enabling "Override X-Plane turbulence."
Hi @jomama. I use ASXP at the "Realistic" setting and have not noticed this. Are you flying into "heavy" turbulence? Although your description doesn't sound like that. You could try turning those settings down as @oisin650advised just to rule that out (or in as the case may be).
And what to do with the difference in the indications of the flight path vectors on the MFD and HUD, you did not say. Will it stay or will you fix it?
206583514_FLIGHTPATHVECTOR.mp4
611123679_Er-rSIDSTAR.docx