YouTube videos aren't playing in safari

MacBook Pro M1, just unboxed yesterday and having the same issue. I have updated to the latest version of Big Sur. I have tried three browsers(Safari, Firefox, and Brave) and none of them will play media on ANY of them. Websites I've tried: Youtube, Netflix, Coursera, Twitter, DailyMotion...you get my drift. Really disappointed. Also, other websites with any form of media, crashes the tab that I'm on. This most recently happened on techradar. The only website so far that seems to work for me is Apple. I have my bluetooth off and am not running any other apps, nor have I installed any extensions. Super frustrating. I have a call with support tomorrow.

I would recommend using a different browser.

Chrome, Brave, or one of the many other choices.

You could also Download Youtube or Netflix for your Macbook.

Best of luck!

How did you go with support? I have the same problem - I can't get Netflix or Plex to work and I've tried Safari, Firefox and Google Chrome.