Thanks for visiting the support forum for QuickBooks, @TH_PERS.

I want to make sure this invoicing reminder concern in your QBO account is resolved. I haven't found any open investigation for the email reminders being automatically sent from the program.

Before we report this concern to our engineers, can you please let us know which browser are you using? Is it also happening when you access your account in a different search engine? Any additional information will help.

Accessing the account on the regular browser will allow the cache to save site settings or memorize account history. 

If you are accessing your account this way, but can't save the invoices settings in QBO, make sure there aren't any third-party apps that will prevent QuickBooks from saving cache.

For now, if the option to send automatic reminders is enabled, you can turn it off using the steps below:

1. Go to Settings ⚙ and select Account and Settings.
2. Select the Sales tab.
3. In the Reminders section, select Edit ✏️.
4. Turn off the Automatic invoice reminders.
5. Select Save and then Done.

Also, it is best to contact our support team since this is a recurring issue for you. This way, our representatives can report this to our engineers for a thorough review. Here's how to contact us:

1. Go to the Help menu in QuickBooks, then choose the Search tab.
2. At the bottom, click on Contact Us.
3. Enter the keyword Account Management and Billing in the What can we help you with? box.
4. On the next screen, scroll down to How would you like to connect with us section.
5. Choose Chat with us to initiate a discussion with a live agent.
6. Enter your account contact info then press Get a chat.
7. When using this option, make sure to enable pop-up windows. The chatbox will appear at the bottom right section of your monitor, and an agent will be with you shortly after.

If you have other concerns with our program besides this invoicing matter, please post here again. We are more than happy to help you out. Have a lovely day, and stay safe!