Hi Vernibob,
Look at this thread…
Poor performance on the ground - Bugs & Issues / Install, Performance & Graphics - Microsoft Flight Simulator Forums
Many of us have had this issue after the last WU… we tried everything in the book to resolve it. The only thing that worked for many of us was unfortunately reinstalling windows. We have tried to bring this issue to the surface… seems like it is continuing to happen to certain users systems.
Rick