In general, sync will try not to create duplicates. In cases when it does, most often it is due to the poor quality of data
provided by banks or our sync providers (Yodlee and SaltEdge). Despite us being in the twenty-first century, these people haven't yet figured
out how to exchange data in a well-structured format.
If you see duplicates, simply delete them and they will not be synced back to your account.