Thanks for getting back to us, ShadyLady.

I appreciate your effort in performing some troubleshooting steps to resolve the issue. Allow me to take over and help you sort this out.

You may want to use terms on your invoices. QuickBooks will treat invoices as DUE UPON RECEIPT if you will not use TERMS in your invoices.

Here's an article with detailed steps and information about payment terms: https://quickbooks.intuit.com/community/Payments/Set-up-payment-terms/td-p/203687.

If you're still getting the same issue, let's try repairing your QuickBooks Desktop. Repairing QuickBooks can to fix program-related issues or errors.

Here's how:

1. Restart your computer to close unnecessary programs interfering with QuickBooks.
2. Back up your QuickBooks company file.
3. Select Start and then Control Panel. (In Windows 8/8.1: From the Start menu, open Search and type Control Panel. From the results, select Control Panel.)
4. Select Programs and Features. If necessary, choose to Uninstall a program.
   (If you don't see these options, select Programs, then Program Features.)
5. Select QuickBooks in the list of programs and choose Uninstall/Change.
6. Select Continue, then Next.
7. Select Repair then Next. Wait for the Repair to complete.
8. Choose Finish. Restart your computer if prompted.
9. Don't forget to download the latest QuickBooks release and the latest payroll tax table when you open QuickBooks.

I've got an article for your reference: https://quickbooks.intuit.com/community/Getting-Started/Fix-QuickBooks-Desktop-Windows/m-p/201490.

Please let me know how it goes or if you ran into a different situation by a reply below.