You provide little information for anyone to know what or where or what setup is causing this if there is or no issue.

Try these values for the following preferences in about:config. ''media.autoplay.default'' = 5 [0:Allowed;1:blocked;5:All Blocked] ''media.autoplay.block-event.enabled'' = true ''media.block-autoplay-until-in-foreground'' = false ''media.autoplay.allow-extension-background-pages'' = false ''media.autoplay.blocking_policy'' = 2 https://support.mozilla.org/en-US/questions/1378457 https://support.mozilla.org/en-US/kb/about-config-editor-firefox