I don't have a direct answer to the problem, but rather an alternative approach. You could import your notes with jimmy. Here are the instructions for the import from Bear:
https://marph91.github.io/jimmy/formats/bear/
I can't guarantee that the import works with this big file size (and that jimmy works on mac at all). The import was implemented on a small example file only. If you have any problem with this workflow, feel free to ask me.
For reference: There was a related thread a few years ago: How to get Joplin to apply Tags from a Bear Notes import?. jimmy should be able to import tags properly.