No, it wasn’t expected! 🙁 Thanks for letting me know. It’s supposed to copy over the old save data to the new structure. The good news is the old save data should still be there so I can fix the copying if I can identify the problem.
It’s working okay for me in Chrome on Windows, so it’ll be hard to debug if something is particularly broken on Mac… If you have time/interest to help me debug by inspecting your localStorage, feel free to ping me on Discord, I’m celia14. But no pressure.