There is an audio startup delay that persists on all websites and is present only in Mozilla. Apparently this problem is a decade old: https://www.reddit.com/r/firefox/comments/39mrox/firefox_html5_audio_delay/ I couldn't find a long-term solution. So far I've Cleaned cache of all websites; Turned off the hardware acceleration and restarted Firefox; Also this problem sometimes randomly disappears, but only until the next restart when it shows itself again. I don't know what to do because I literally can't use some websites in Firefox