I would get this issue out into the main forum, you might be limiting potential replies with help because this is a GPU driver thread. Do you have any other third-party AC that you can try? It sounds like this issue may be associated with your default AC only? Something to do with Virtual Cockpit mode and perhaps refresh rates in VC mode perhaps? The fact that you have a new fresh install might make it easier to diagnose. Your not using VR are you?
Have you tried reducing your instrument update-rate and then taxiing? Try changing the setting for the VC refresh rate instruments in the options and save the settings. Perhaps re-start the simulator and change the setting back to where it was when you had the problem and see if anything has changed for the better.
I am not convinced that a re-install has cleared out/removed and updated all the MSFS 2020 directories on your computer. You may still have some older .cfg files that are are being used now that were left over from the previous install! If I had to uninstall MSFS 2020, I would probably manually check the PC for left overs, (files and folders) back them up and delete the left over originals. If you did not have to re-register the new installation again, then there had to be something left over.
Could there be a clue here …
Charles