For many years now I've had Firefox clear * browsing & download history * temporary cached files and pages * saved form info but ''not'' * cookies and site date * site settings This worked flawlessly until Firefox updated to version 136, at which point ''all'' cookies were deleted and I was signed out of every account on every website. Looking at the settings page, the option to delete cookies and site data when Firefox is closed is now enabled. I don't remember what this setting used to look like, but ''I did not change it recently.'' Unchecking the box seems to work, but I shouldn't suddenly have to do this, and the "damage" is done. Why did the update to version 136 sign me out of every website, and ''how do I protect myself against this happening again?''