Problem 

When you try to sign in to Microsoft Teams in Chromium Browser, the site loops continuously, and you can't sign in. 

For more information, see https://learn.microsoft.com/en-us/microsoftteams/troubleshoot/teams-sign-in/sign-in-loop#resolution.

Solution

For Microsoft Teams to work in Chromium Browser, it is required to allow the use of cookies. You can allow the use of all third party cookies in Chromium Browser by disabling the Block third party cookies parameter under Sessions > Chromium Browser > Chromium Browser Global > Privacy.

You can also configure cookie exceptions while keeping third party cookies blocked through adding a custom policy:

  1.  Go to Sessions > Chromium Browser > Chromium Browser Global > Custom Setup > Policies.

  2. Click   Add to create a policy.

  3. For Policy name, enter: CookiesAllowedForUrls

  4. In the Policy value field enter the following list of URLs: [[*.]microsoft.com; [*.]microsoftonline.com; [*.]teams.skype.com; [*.]teams.microsoft.com; [*.]sfbassets.com; [*.]skypeforbusiness.com]

  5. Save the changes.