ginga-ninja1608 Are you missing all saves, or only some? The Main Menu can only display a certain number of saves at a time. How many varies from one computer to another, but if you think that might be your issue, move most of your older saves elsewhere and see whether the new ones appear.
If all of your saves are missing, please right-click one save and select Properties > General, then list the Location. It's possible OneDrive is moving your data to cloud storage, in which case the game won't see or be able to load it.