Hi there, @CayceMB.

Let's perform some troubleshooting steps so you can turn off the Automatic invoice reminders option in QuickBooks Online (QBO).

There are times when the browser you're using has data issues, thus causing QuickBooks to act weirdly. To verify, let's log in to your QBO account using a private browser. To do so, press this shortcut key on your keyboard:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P

Once logged in, go back to the Account and settings and turn off the option again to double-check. If this works, you need to clear the browser's cache so the system can start fresh. If you get the same result while using a private browser, I suggest switching to a different one.

If the issue persists, I recommend contacting our QuickBooks Support Team. This way, they can further check on this matter and provide in-depth troubleshooting steps to get this resolved.

Just in case you want to learn how to manage prior balance for a customer that owes you money, you can check out this article for more guidance: Manage outstanding balances for customers in QuickBooks Online.

Come back to this post if you have other concerns or follow-up questions about this. I'm always here to help.