If Outlook keeps asking for a password, emails are not fully downloading, calendar is not working properly, etc. This steps will most likely solve the issue.
Troubleshooting
If you are using a Mac, close Outlook. Then open Keychain Access by pressing Command+Spacebar, type "Keychain Access" and then hit enter. It will look something like this:
In the sidebar on the left, make sure that 'System' is selected. Verify that 'All items' is selected, as well.
Then search for 'microsoft' in the search bar at the top right side of the screen.
Select all of the items and then right-click. Select "Delete 16 items" (our screen says 16, but yours may be different).
After that is done, restart the computer and try to login to Outlook normally.
If performing these steps doesn't fix the issue the next step is to reinstall Outlook 365.
If you have any further questions please contact us by submitting a ticket through the following link: