I was able to open the zip file, and the save loaded fine here, so the issue isn't a problem with the save itself.
Other than the install folder, there should just be the '../Documents/Larian Studios/Divinity Original Sin 2 Definitive Edition' with the saves, profile(s) and configuration files for the game.
FWIW, there is another game update being prepared, to be released in the new year. The game update could potentially fix / reset / avoid whatever the problem is currently, or maybe after a break you'll have the patience for some more troubleshooting.
