Spotted this earlier today, in the Outlook app on Android, while I was reconnecting my Facebook calendar to my Outlook calendar.
It looks like you entered a slight misspelling of your email or username. We’ve corrected it for you, but ask that you re-enter your password for added security.
I see this a potential security issue, especially if someone is guessing which username / password you’ve used but has the password. Thankfully it’s not too much of a problem if you have two-factor authentication enabled, but it’s still a potential security issue.