Hello there, @hello129.

The Automatically apply credits option should still be available in the Account and Settings' Advanced menu in your QuickBooks Online (QBO) account. Let's perform some troubleshooting steps to help fix this unusual behavior of the system.

There are times that the browser is full of frequently accessed pages, thus causing some uncommon responses. To isolate this, you can log in to your QuickBooks Online (QBO) account using a private browser (incognito).

Here's how:

• Press Ctrl + Shift + N (Google Chrome)
• Ctrl + Shift + P (Firefox or Internet Explorer)
• Control + Option + P (Safari)

Once signed in, go to the Gear icon, select the Account and Settings menu, then go to the Advanced tab to activate to turn on the Automatically apply credits option. 

If it works, return to your default browser and clear its cache and cookies to refresh the system. This will also remove the older data which can potentially cause viewing and performance issues. However, if the issue persists, I'd recommend using other supported browsers to enable the said feature.

In case non of the suggested steps above worked, I'd recommend contacting our QuickBooks Online Support team. They can further investigate the behavior of your account and can guide you with its resolution.

To view the complete list of your customer credits, you can pull up the Transaction List by Customer report. Then, customise it to filter the Transaction type to display the Credit note for each customer.

Please let me know if you have other concerns. I'm just around to help.