Firefox 86: total cookie protection: strict enhanced tracking protection (ETP) is no longer immediately compatible with Microsoft Teams web app

Synonyms:

After three failed automated attempts to load (or remain loaded), the Teams page may present this error:

To open the web app, {{aTagStart}}change your browser settings{{aTagEnd}} to allow third-party cookies or {{aTagStart}}allow certain trusted domains{{aTagEnd}}.

https://bugzilla.mozilla.org/show_bug.cgi?id=1693768 became a duplicate of:

For reference, I’m aware of three workarounds:

  1. step down from strict, to basic (least desirable)
  2. disable protection for the site (quick and easy)
  3. allow cookes and site data to be always used by a related site.

The screenshots below are to guide readers through the third approach.


  1. Click the shield (ignore the hint about no known trackers)

  1. visit the Protections Dashboard

  1. Manage your privacy and security settings

  1. :warning: ignore the first Manage Exceptions… button

  1. use the second Manage Exceptions… button

  1. type this address

https://login.microsoftonline.com

– then Allow

  1. Save Changes

  1. bring the Teams web app to the front, Try again