should Firefox for Linux have audio on this website?

[Skaperen]

should Firefox for Linux have audio on this website or is one or the other broken (or misconfigured), and which?
https://www.senate.gov/legislative/floor_activity_pail.htm
i am running Xubuntu 18.04.6 with Linux 5.4.0, Firefox 95, and PulseAudio 11.1 (running in system mode)
videos from Youtube play both video and audio just fine on Firefox.
please do not suggest any alternate software unless buildable source is available for free and anonymously.

[october262]

audio works ok on on my linux system using Firefox.
did you try clicking the volume adjustment boxes next to the speaker in the video ??

[Skaperen]

audio works ok on on my linux system using Firefox.
did you try clicking the volume adjustment boxes next to the speaker in the video ??

yes, i tried that box. it was already at full volume.

there must have been some transient problem as visiting it today has proper sound. i did quit Firefox and start it again, previously, to make a new connection, and still got silence. a connection to YouTube (a separate instance of Firefox) worked just fine. so, i was thinking it might be a case of some proprietary encoder issue.