Hey @beejumm! If it’s any consolation, I also described this exact same issue a few months ago: Duplicate cards submitted to AnkiHub (same note IDs) when forgot to sync with AnkiHub on new computer. I agree it’s really annoying and I’m glad the team are looking into it! If it’s any help in the meantime, the only way I somehow attempted to minimise it happening personally was ensuring that you try and actively avoid edits to cards before they have been synced with AnkiHub on a new device. I found the issue seemed to happen when I forgot to first sync the cards with AnkiHub on the other computer I signed into AnkiHub with and then proceeded to make some edits to the notes/cards (which appeared because of the normal synchronisation with AnkiWeb) and then “bulk suggest notes”. It would then submit the note with the edits thinking it was a “new card” perhaps because it hadn’t been synced yet, even though the exact note ID was the same as the existing card on AnkiHub so ideally should have been rejected. This understandably caused subsequent problems with syncing as a result. All the best 