Welcome to the Community, @jac-ellen. I'm here to help get your online banking to reconnect so you can start downloading transactions.
Let's perform a manual update to refresh the connection and bring in your transactions. Here’s how:
Go to the Banking tab on the left panel.
Choose Banking, then click on the Update button.
If you’re unable to connect, please wait for 2 or 3 hours and try again.
If you're still getting the same error after 72 hours, I recommend contacting our QuickBooks Online Support to check the connection between your bank and QuickBooks. We can also request to investigate the issue whenever necessary.