If you get through that fight on PC, do/did you have any problems with subsequent combat in Reaper's Coast?
Try clearing the system cache: in the Home menu open System Settings, then select System, Formatting Options, Clear Cache and then the current user.
Note that this will also reset the system language and brightness setting.
If that doesn't help, please reply with a save before that encounter (or a Dropbox or Google drive link, etc), and if possible, a save made during combat where the crash can be most easily reproduced (if it isn't completely random; if it is, just any save mid combat).
Once synced, 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' (and similarly in OSX/Finder).