Using the Steam Cloud Manager program, check the details of the online saves and compare them to the ones in your '..\Documents\Larian Studios\Divinity Original Sin Enhanced Edition\PlayerProfiles\<ProfileName>\Savegames_patch' folder, and see if they have the same time stamps, or earlier.
Alternately, you can just download the latest cloud save stick it in a different profile's savegame_patch folder (or rename the save folder and files in it keeping them matching, and place it in your existing profile), then load the save and see if it matches the current one or not. Having it match is more likely, but if Steam didn't sync, you can still get the version from the last time it did.
