Thanks for the prompt response, @accounting476.

I'm here to provide some details regarding the error and ways on how to fix this.

Several factors could cause error code 386, such as a typo, an outdated account number, or a system glitch.

Have you recently updated your account information on your bank's website, like your password, username, or account number? If yes, you need to update it in QuickBooks too: 

1. Go to Banking.
2. Locate your bank account, then select the Edit ✎ icon.
3. Click Edit sign-in info.
4. Update your info as needed.
5. Select Save and Close.
6. After saving your bank details, click the update button located at the top right part of the banking page.

If this didn't fix your problem, I recommend contacting our Support team to ask for an update: QuickBooks Online Support.

Additionally, you can check this article Learn how to reconcile your accounts so they always match your bank and credit card statements: Reconcile an account in QuickBooks Online.

Keep us posted if you have further concerns on this issue. We'll always be here to help you.