Hello there, @chillertron.
Thank you for posting in the Community. Let me help share some information about logging in to QuickBooks account through the Windows Application.
I've checked and found out that there's an ongoing issue with using the QBO App for Windows. At this time, our Engineering Team is working to get this issue resolved as soon as possible.
In the meantime, our temporary workaround is to use a browser when logging on to your QBO account. While they continue working on this, I suggest giving our QBO support a call so that we can add your company details to our containment list. You will then be notified with the latest update via email.
Here's how to get our contact information:
Please know that you're always welcome to visit us again if you have other questions about the QBO App. I'll be here to help.