Outlook Disconnected MFA causing issue
Hello, have researched all over for this specific issue and have came up with a lot of information, however, no permanent fixes. Have some mailboxes that seem to keep going into disconnected checking the status shows Authn Error. The issue seems to be with MFA and Outlook somehow going into basic auth(My best guess) because whenever MFA is disabled one the account it works properly connects, etc.. This is happening with the Office 365 on the newest update. Also hybrid setup with local AD and 365 sync. Things that have been tried:
Microsoft's regedit to force modern authentication
Recreating the windows profile (Did this and a user called back the next day with Outlook disconnected)
Running Microsoft Sara
Reboot (will fix temporarily then break)
Clearing all creds in credential manager
Clearing out the identity key in registry under Office\16\common
I haven't tried reaching out to MS and see if there's something they can do, I'm out of ideas and all the fixes that worked for others definitely haven't worked for me.