I am currently trying to fix an end user that is unable to login to the outlook desktop app. I made a change in ADSI edit and changed the primary proxy addresses SMTP:[email protected] to the domain requested to be used. Then changed the domain in O365 admin to the updated domain. User was able to sign into mobile app and web app but no longer able to sign into the desktop app. I see the following in O365 Admin This occurred due to 'Keep me signed in' interrupt when the user was signing in. , Due to a configuration change made by your administrator, or because you moved to a new location, you must use multi-factor authentication to access '{resource}'. & Strong Authentication is required.
I have since reverted the changed and returned user to the original domain, cleared credential manager, enabled MFA, reinstalled O365, and user still cannot log into desktop app. What else can I check?