No sound while watching peertube on Linux Firefox 135

Hi, I am trying to watch Peertube videos using Firefox 135.0.1 on Gentoo Linux x86_64 laptop, and I get no sound. What’s going on, how this can be fixed/debugged?

I do have sound etc on YouTube (same browser used), on various other web apps, so that’s not that I have broken sound support on the system.

Thanks,
Dima

I can add that I can also view downloaded mp4 in vlc on this machine just fine, with sound and all, but in the browser the file plays without sound, and the sound icon is crossed over.

Ensure your web browser has been compiled with AAC audio support