I’m not able to reproduce this - I export an apkg with the latest beta version making sure the legacy import/export code is not enabled in the preferences screen, and import it into a different profile. Then I add a tag, export and import into the other profile, and the note has been updated.
It seems the cards weren’t the exact same. The note type on his AnKing version was ClozeAnKingMaster, while mine was AnKingOverhaul. Changing all his cards to AnKingOverhaul has helped everything update successfully.
Apologies for the incorrect information, but thanks again everyone