You can always login to your computer with the local user, as long as you have logged in before.
This is a backup login option used in circumstances where online login is not possible.
On the sign in page, select the icon of a person in the top right:
Then, type in your username and password. Your username is your email without @northmen.org, and your password should be your microsoft account password.
Please let us know if you are still having issues.