I have the problem asked in [[https://support.mozilla.org/en-US/questions/1297208]], and indeed I had turned on/true privacy.resistFingerprinting. But I've turned it off and reloading https://webbrowsertools.com/timezone/ still shows UTC time (though my system timezone is -0700 (CST)). I was going to ask what is wrong, when I realized I have to restart my browser. So submitting with that solution.