Thanks for reaching out in the QuickBooks Community space, @Carola1. 

Sometimes local internet cache files stored in the system can cause unexpected behavior in the product. This might be the reason why your invoices are showing as paid even if they're not. 

Let me share with you some basic troubleshooting steps that will help you fix this right away.

To start, open your account in a private window. This is mode doesn't save your data activity on your device and to any browser you're signed into.

 Here's how:

• Press Ctrl + Shift + N (Google Chrome).
• Ctrl + Shift + P (Firefox).
• Control + Option + P (Safari).

Then, sign in back to QuickBooks and check if the status of your invoices is now correct. 

If yes, go back to your regular browser and clear its cache. Alternatively, you can use another supported browser. 

If the issue persists, you can reach out to our QuickBooks Customer Support Team. That way, they can trace the cause of the problem and fix it. You can also share your details with them so it would be easy for them to address the issue. 

For additional information in recording customer payments, please check out this article: Record invoice payments in QuickBooks Online.

Please leave a comment in this thread if you have any other questions or concerns, Carola1. I'm always here to help. Have a good one!