Hello there, phoenix6.

While we don't have a report that shows only those closed sales orders, you can run the Transaction Detail report and customize the filter to show all the Sales Orders (SO). From there you can manually locate and edit each SO transaction to Mark as Open.

Here are the instructions below:

1. Go to the Reports menu and choose Custom Reports.
2. Then, select Transaction Details.
3. Click the Customize Report button.
4. On the Display tab, set the date range for the affected transactions. In the Columns section, select Trans #.
5. From the Filters tab, search for Transaction Type.
6. Click the Transaction Type drop-down arrow and choose Sales Order.
   
7. Search for and select the Posting Status filter, then choose Non Posting.
8. To generate the report, click OK.
   

Then, locate the closed SO and click it to open the transaction. From the Main menu, Click the Mark as Open icon. This will re-open the closed SO. I've added a screenshot below for your visual guide:

Here's a great article that will guide you through the steps on how to reopen SO's in QBO: Some Sales Orders or Estimates may be incorrectly marked as closed.

Learn more about customizing reports in QuickBooks Desktop through this article: Customize reports in QuickBooks Desktop.

If you have other questions or need further assistance, please know that I am here for you. Update this thread or start a new post in the forum. Have a nice day!