If you start a new game and save on the Switch, does that sync to PC? Does a new game on PC show up on the Switch?
On PC, other than restarting the game, you can confirm what saves have been synced online with the program
Steam Cloud File Manager Lite (
download), which can also download, delete or upload saves. You need to be logged in to the Steam client and have the game's AppID (435150).
Alternately, you can log into Steam in a browser and use
this link (that will also let you download saves, but you would need to manually rename them, as Steam combines the path and name together for the online name).
On the Switch, try clearing the system cache: in the Home menu open System Settings, then select System, Formatting Options, Clear Cache and then the current user.
Note that this will also reset the system language and brightness setting.
On PC, try clearing your Steam client cloud cache: exit out of Steam, in the Steam install folder browse to the 'userdata' folder and find the game's folder ('435150'; it will be in a numbered folder which is different for each user), then delete the 'remote' folder and remotecache.vdf file there, restart Steam and then D:OS 2. If there are multiple Steam ID folders with '435150' subfolders, delete the contents of each.
C:\Program Files (x86)\Steam\userdata\<SteamID>\435150
Try connecting the Switch to a different network, and see if that allows the saves to sync back. For example, one person could sync (PC to Switch) if they used their phone's mobile hotspot feature, but not their home network (which worked for the original Switch to PC sync). Depending on where you live, various stores, restaurants or libraries, etc, may have free wifi, if you don't have access at school/work or a friend or neighbour's house.
Check on the Switch if the date and time listed for the cloud saves are the same as on PC, in case a time zone setting difference is causing problems with syncing.
