This error can occur if QuickBooks is unable to verify your bank's website. There are two ways to ways to get rid of this error. You can either reconnect or update the connected account manually, or connect a new one.
Let's try the first solution which is reconnecting or updating your account manually. Let me show you how:
- Select Reconnect my account after the error message.
- Choose the updated account with your bank.
- If the Reconnect my account link is not available, click the the Update button in the Banking page.
- Enter the Multi-Factor Authentication (MFA) credentials.
- Select Continue update.
You can also follow Solution 2 in this article if you need more troubleshooting steps to resolve the error: Fix Banking Error 324 in QuickBooks Online.
I'll be around if you need anything else.