Estimate showing unbilled items that have been billed and paid

I appreciate you sharing the steps you've taken to resolve your estimates showing unbilled items, DB2. I'll gladly help you so you can resolve this issue. 

In QuickBooks Online, once you convert or link the estimate to an invoice, this will be automatically removed from the unbilled list. Since you've mentioned that it was still unbilled although they were invoiced before, you may have linked or converted the incorrect estimate. Thus, you saw Service Instead of Construction Labor in the invoice line item. To correct this, you need to check if you linked the correct estimate to the invoice by checking the date when the estimate was created, the estimate number, and the line items. If this is not the correct estimate, you can remove the line items and add the correct one. 

Here's how:

1. Go to Sales, then select Invoice.
2. Find the transaction you've linked to the estimate, then click Edit.
3. Click the Manage icon, tap the Suggestions dropdown, and click the Suggested Transactions hyperlink.
4. Select Remove to unlink the estimate, then click Add to link the correct one.
5. Once done, choose Save and Close.

Additionally, you can run an Estimates & Progress Invoicing Summary by Customer Report to view all your linked and unlinked estimates and their statuses and other details. 

Also, once your customer has paid the invoices, you can record the payment in the program to mark the existing transaction paid.

If you have any other questions or concerns regarding the management of your estimates or any other aspect of QuickBooks, please feel free to leave a reply below. I am always available to provide further assistance. Take care and stay safe!