Hello there, @Soph0115.

I'll help you update your American Express bank account in QuickBooks Desktop. It will fix your issue and ensure the latest transactions will be downloaded.

Before doing so, make sure to create a backup of your company file and update to the latest release.

Here's how:

1. Go to the Banking menu, then choose Bank Feeds.
2. Select Bank Feeds Center.
3. Click the Refresh account(s) icon or choose Sync all for this bank from the dropdown.

For future reference, you can read this article about matching transactions: Add and match Bank Feed transactions in QuickBooks Desktop.

Let me know if you have questions about bank transactions. I'm always here to help. Have a great day.