The AI tab thing is a problem for me for multiple reasons. I found various articles about how to turn it off. They pointed to the following setting: In about:config set the setting "browser.tabs.groups.smart.enabled" to false, and then restart Firefox. However, when I do that, and then immediately go back to about:Config to check the setting, it has changed itself back to "true". Other settings accept and keep permanent changes. This means that I'm not forgetting to save the change or anything. Just this one setting (which turns off something causing me problems) refuses to actually stay set. I see the answer to this question https://support.mozilla.org/en-US/questions/1509077 and tried looking there. There is a completed study called "Smart Tab Groups Rollout", but since it is in the "Completed Studies" group, I cannot remove it.