Using Outlook for Android for personal email and calendar management
I have been having the same issue on both my phones running Blackberry Hub on my Android Pixel 6a's
I chatted with MS tech support who suggested turning on 2FA, then getting an app password, and using that as my mail password for my one Android phone. I got the same authentication error. the agent suggested it was a blackbery hub issue and to contact them.
This morning my phone is getting some email, but still getting Authentication errrors on both Outlook accounts on my phone, even the account I didn't adjust, (so both accounts giving errors, getting emails, even though I only changed settings for one of them
Likewise, my wife's phone hasn't received anything since Tuesday on our shared outlook mailbox.