Hello there, moderndayretro1-,
The error "This XML file does not appear to have any style information associated with it." is a warning that the browser is unable to display the XML correctly.
We can do browser troubleshooting to resolve this. Let's start with accessing your account using a private browser. This mode will not store the cache and cookies. Next, go to https://qbo.intuit.com and log in to your account.
Once logged in, try connecting to your Monzo account again. If it works, clear the cache in your regular browser. This helps freshen up the browser settings.
Here's an article that include the steps on each browser: How do I clear my browser cache and temporary Internet files?. You can also try using a different browser.
Let me know if there's anything else I can help you with.
