We had converted a couple exchange mailboxes on 365 to shared mailboxes that users were logged into on Outlook. When we did so we wanted to log into those shared mailboxes to add them as accounts basically. To do this you use the option in the password prompt to log in as different user. The reason for this is because searching that mailbox does not work when searching outside the mailbox using "Search all Mailboxes. Microsoft has confirmed the issue it seems and this was their work around.
Anyways when we converted these exchange accounts, we went to the users Outlooks and it was asking for the exchange password for that account (I guess it was still thinking it was a exchange account?). I went and removed the account from Outlook and relaunched Outlook and the now shared mailbox was there correctly. Again the next steps now are to add the account manually instead of using the automapping. But when we type the email in, it goes to the password section and only offers change password and no sign in as different user option.
We have tried turning on the cached mode, deleting the old exchange OST file, tried turning off "Use Cached Exchange Mode" under the advanced settings in Account settings, Nothing in credentials manager. When adding myself as a member and letting automap do its thing then trying to login gives me the option fine. The only difference I can see there is they were signed in to the exchange account when converting the shared mailbox.
