I'd be happy to assist you with connecting your bank account into QuikBooks Online.
If you're connected to QuickBooks Online Banking, your transactions should sync automatically on your QuickBooks. However, running a manual update can also help to refresh the connection between your bank and QuickBooks.
If the problem continues after trying the update, I'd suggest getting in touch with your financial institution to verify if they have conducted system maintenance.
Also, if you encounter any online banking issues, you may check out these articles for some troubleshooting steps: