When I save my invoices it comes up as paid

Hello, sefo-tauilo86-ho.

It is possible that automatically credits turned on. Once its enable, the system will tag the invoice as paid even if they haven't been paid yet.
 

To turn it off, you can follow the steps below:
 

1. Click the Gear icon.
2. Select Account and Settings.
3. Go to the Advanced tab.
4. Press the Pencil icon in the Automation row.
5. Uncheck the Automatically apply credits box.
6. Tap  Save, then Done. 

These will prevent the system from applying credits or unapplied payments to the open invoice automatically.
 

If you wish to apply credit memos and delayed credits in QuickBooks Online, refer to this article: Create and apply credit memos or delayed credits in QuickBooks Online.

Just in case, I'll be adding these articles for future reference on how to manage your invoice transaction:

• Record an invoice payment.
• Send invoice reminders automatically or manually in QuickBooks Online

Let me know if there’s anything that I can help with your invoice by leaving a comment below. I’m always here to assist. Take care and have a wonderful day!