Welcome to the Seller Community!
Sorry to hear about the trouble with the duplicate estimates. To be sure I'm on the same page—is this happening when you create an invoice with Point of Sale, or are you creating an estimate with Square for Retail?
If you're still seeing duplicates, these dashboard troubleshooting tips may resolve the issue: Square Dashboard Troubleshooting. Otherwise, feel free to send over more information on where you're seeing the duplications and I'll be happy to escalate this further for a closer look!