I think I found a bug (didn’t find a GitHub issue for this) with Meta Box integration.
→ You can’t use Meta Box subfield of a Meta Box Group (from a Setting page) inside Oxygen Repeater.
GitHub link: https://github.com/soflyy/oxygen-bugs-and-features/issues/2669
Please, upvote it if you’re using or planning to use Meta Box, it’s important and a nice feature that we can’t use right now…
I don’t know if you already know this issue Elijah Mills?
Might be good to know if that’s the case and you’re working to fix this for the Oxygen 4.0.