I was only able to reproduce the hanging loading process by changing mods. That may be why the fix that worked for me (re-saving with the updated mod configuration) did not help you.

Can you reproduce this problem with any mod and one of the default GM campaigns? If so, how is it triggered besides saving in a scene, quitting and restarting?

Please email supportdos2@larian.com with a save where this has happened (or a Dropbox or Google drive link, etc), if possible, as well as a list of the non-Larian mod(s) used.
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2 Definitive Edition\PlayerProfiles\<ProfileName>\Savegames\GM' folder.
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder' (and similarly in OSX/Finder).