If you load the save without any mods enabled, does that make a difference?
Did you try waiting a while?
Try lowering the graphics settings and resolution, and switch to Windowed or Fake Fullscreen display mode, to see if that helps.
Try verifying local files: in the Steam library, right click on the game and select Properties, switch to the Local Files tab and then click on the 'Verify Integrity of Game Cache...' button.
If that doesn't help, please email supportdos2@larian.com with your save (or a Dropbox or Google drive link, etc), and a link to this topic.
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2 Definitive Edition\PlayerProfiles\<ProfileName>\Savegames\Story' folder.
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder'.
