Thank you for taking the time to visit the Community to post your issue, although I apologize that you haven't received a follow-up response.
Please take a moment to navigate to Help > About Quicken and post back with the year and version of Quicken you are currently running.
When did you first see this duplication? Did any changes or events occur prior to this happening?
If this after an update, have you tried restoring a backup prior to this occurring?
https://www.quicken.com/support/how-backup-or-restore-your-quicken-data
Please let me know!
-Quicken Tyka