Firefox won't let me log in with MS Teams

Since June 2022, the Mozilla Firefox browser supports Total Cookie Protection by default. As a result, some Kanban Tool clients may experience difficulties when logging in to a Microsoft Teams-integrated account with the “Sign in with Microsoft” SSO option. The login screen may loop indefinitely, failing to complete the login action.

To solve the problem, please click on the shield icon in Firefox address bar Opening the cookies protection shield in Firefox

and disable the Enhanced Tracking Protection is ON for this site option: Disabling enhanced tracking protection in Firefox

That should let the page complete the login procedure.

If it did not help, please click the shield icon again, and go to Protection settings:

Accessing protection settings in Firefox

Under Enhanced Tracking Protection, click the Custom option and apply the Cross-site tracking cookies selection:

Allowing cross-site tracking cookies in Firefox