Hi there, Goodweather.
I'm here to help you sort this out.
When a name shows the amount of 0 under the total in the AR Aging Summary report, that name should not show at all. You can double-click the total amount of 0 to see the unapplied transactions. I'll show you how to fix it.
1. Go to Receive Payment for that name.
2. Leave the amount as 0.
3. Select any open charge balance.
4. Check at the top part if you see Apply available credits.
5. Click Save and close.
Also, if you had applied them and still see the invoice has the status of past due. You can run Rebuild this file to fix minor issues on your company file.
I'll include this article in case you want to customize the report in QBDT. This contains steps to generate a report base on your preference.
Reply to this post if you have further questions about your account. We're always here to back you up. Have a great day!