Are you aware that the co-pilot screens can be turned off? make sure you turn the middle of the brightness control dials anti clockwise on the co pilot side fully so the screen disappears. It will on some systems take a minute or so for the sim to catchup and realise it’s no longer needing to do the calculations. I dare say that on the ground performance is perhaps something that has been introduced with the recent updates? “Overkill” from youtube has released a video in the past few days pointing to a vr issue with the steam software which can actually cause stuttering & pauses and seems to affect things regardless of wetrher you us VR or not. Altough I bought the boxed version and registered my code from the MS Store, I do have steam installed so I will be checking into this myself later.