OData or sharepoint list oAuth2 authentication not working

I stumbled on this thread today while researching what sounds like a similar issue.

As with others on this thread, things had been working as expected for us over the last few weeks/months, but we're now suddenly experiencing this issue. MFA was enbled for our users 20 days ago, and several users are now reporting encountering this.   

We opened a Premier Support case and have passed along the information contained in this thread. Our Support Engineer suggested that we update Power BU Desktop, uninstall/re-install the Gateway, and ultimately took a Fiddler trace. While he's analyzing the collected data, we're going to try to add preview.powerbi.com to our Trusted Sites (can't do so locally due to Group Policies), then whitelist IP ranges for this and the various regional clusters (e.g., https://wabi-north-europe-redirect.analysis.windows.net).

Please let us know if you receive any updates on your collective cases and we'll do the same.