Okay, I think I figured this out. My other computer running a different linux distro but the same version of firefox (version 128) didn't have this issue, which pointed toward a config issue on Linux Mint. After searching my entire disk for any "*mozilla*" file I found this config: /usr/lib/firefox/mozilla.cfg which contained this line: pref("places.history.enabled", false); This is the stupidest idea I've seen on a linux distro yet. Overriding user configs with a systemwide config and don't let them know about it??? Grrrrrr!!! This explains why every attempt I made to update/uninstall/reinstall and create and delete profiles resulted in a failure to get firefox to remember History settings. Everytime I restarted firefox the places.history.enabled was turned off by this config file.