Good morning CraigSpring,
It sounds like the sync pending is a message you're seeing letting you know that the sync hasn't completed. It may still be pending because of the connection. Are you able to test the PC on another network to see if there are any issues? A VPN or security software could also be preventing a strong connection.
Just to confirm, while logged into iCloud on a web browser do you see the files in iCloud Drive? Is this how you added them, or did you add them to iCloud Drive using a different device?
If you're still having trouble, try reinstalling iCloud for Windows by uninstalling it first. Follow the steps under "Turn off or uninstall iCloud for Windows" here: Set up and use iCloud for Windows - Apple Support.
Take care.