I've been using Edge on Windows for a couple years now but I've also installed it on my Linux machines at home. On two separate machines, bot running Pop!_OS 21.04, GNOME version 38.5, and Edge version 95.0.1020.14, random tabs will stop playing audio and those websites will no longer play audio.
It started on the site songsterr.com where it plays a midi track and the audio one day stopped playing. I've tried closing edge and rebooting the machine but it just stopped working. This site doesn't work on either machine. For Songsterr, it also shows that audio is playing, and I can mute and unmute the tab, but audio still doesn't play. YouTube works fine, other streaming services such as Plex or Netflix work fine, it's just these tabs. These tabs also worked prior, then I'd leave my machine, come back, and somehow they're not working.
Yesterday, it also stopped working on a couple streaming sites such as nflbite.com. It seems to carry over between machines, and it doesn't matter if I'm using wired headphones through a DAC, wireless earbuds or wired speakers, nothing works.