First Party Isolation is part of their quest to re-import privacy features from the Tor browser. It basically completely isolates every domain. You can look up the about:config values to enable it (they're at the bottom of the article too).
IIRC I had it enabled for about a year with no breakage, but about a month ago it suddenly broke my university's login system. But I just turned it back on and that login is working OK again.
Also probably would be good to enable browser.cache.cache_isolation.
First Party Isolation is part of their quest to re-import privacy features from the Tor browser. It basically completely isolates every domain. You can look up the about:config values to enable it (they're at the bottom of the article too).
IIRC I had it enabled for about a year with no breakage, but about a month ago it suddenly broke my university's login system. But I just turned it back on and that login is working OK again.
Also probably would be good to enable browser.cache.cache_isolation.