I can help connect your RBS account in QuickBooks Online (QBO) successfully.
First off, let's verify your bank login credentials by signing in to your bank's website. If the credentials are incorrect, I suggest contacting your financial institution to help reset your login. If it's correct, you'll want to make sure that the credentials you enter when connecting your RBS account in QBO are accurate.
However, if you get the same result, let's perform some troubleshooting steps to get this resolve. To do that, let's try logging in to your QBO account using a private or a different browser. This way, we can check if it's a browser data issue.
Press Ctrl + Shift + N on your keyboard for Google Chrome and Mozilla Firefox.