@gnomeweb @MicrosoftToDo nailed it. Because I am using an Outlook/Live MS account, it authenticates through http://login.live.com rather than http://login.microsoftonline.com, so I had to add http://login.live.com to the “Manage Additional URLs” list under Preferences.

@gnomeweb tried a different app and it was fine. The issue is with @MicrosoftToDo, it doesn’t seem to want me to authenticate within the site specific browser instance.

@gnomeweb oh, I see, it’s not available when installed from flatpak (and @fedora defaults to flatpak in Software).

However, even when I got it running, and ran a web app, it opened firefox to authenticate and never came back to the web app?

I love that @awscloud persistently warns me about exceeding my free EC2 instance hours, which is impossible to do with a single instance but totally failed to warn me I HAD exceeded my EBS snapshot storage.

¯_(ツ)_/¯