Bookmarks and browsing history are not separated by Container Tabs. So, it will sync both personal and work bookmarks, just like it would without Container Tabs

Bookmarks and browsing history are not separated by Container Tabs. So, it will sync both personal and work bookmarks, just like it would without Container Tabs. The idea being that you look towards the internet like several users, but on your end it still behaves like a single user. If you do want bookmarks and browsing history separated, then yeah, as the other guy said you'll want to use classic profiles. Easiest way is to type "about:profiles" into the URL-bar and then the rest should be self-explanatory. Another (scriptable) way is explained here: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles https://support.mozilla.org/en-US/kb/profile-manager-create-... And then you'd create a second Firefox Account and give each profile a different Firefox Account to sync to.