I’m guessing latest update to Version 100, is most likely culprit. Thank God there is a update history and that’s the last update I did. The previous update was 2 days ago on May 5th. YouTube has sound and Twitter sound works in Google Chrome. So I guess I wait and use Twitter in Google Chrome.
Ok I got sound working by accident. changed Output Profile in Sound Settings. For example Analog Surround 4.1 Output. Have been having random problems with Firefox sound where the sound randomly, sometimes in the same video, would get very distorted until I changed Output Profile in Sound Settings to anything else. Often just back to the original setting.