[2022] Steam Cloud Save Upload not working (Windows Laptop to Windows Desktop)

Does this also affect CK2 ? It uses the same Steam cloud processes to save there.  

Hard to see what could be wrong on that laptop then, or in the Steam installation on it.

You could try a clean Steam reinstall:

- delete everything in the Steam folder EXCEPT steam.exe and the SteamApps folder
- run steam.exe to rebuild all that