Hello! Everything was fine until I briefly used a VPN extension for maximum 10 minutes (it's UrbanVPN), and when I returned to the tab with the youtube video on it, it had no sound (I've used this particular extention plenty of times, it's the first time this has happened, also I don't know if it has anything to do with the extension, I just thought I should mention it). Laptop is fine, all sound everywhere else works perfectly, except from any video played from the mozilla browser. I took some advice from online: I restarted the computer, I selected troubleshooting, I typed about:profiles and selected 'Restart normally', nothing has worked so far. The only thing I haven't done yet is disabling graphics hardware acceleration, an advice from mozilla support for a similar problem a person had 6 years ago (no sound on youtube), but I can't find where that is, maybe because I have the latest mozilla version. Could you help me?