Firefox: no sound


I know it is a frequent topic, so if you have a link to respond, it will be enough for me.

I didn’t install a server with, I use the website

I’m using Firefox 77 and I get no sound from other people. In a conference, other people can hear me, but I can’t hear them. I’m using windows. At home there is no problem, everything works fine. On my workplace, the audio doesn’t work. I assume also there is a network problem.

What do I have to check ? A port ? If yes, how to check if a port is open or not ?

The problem happened yesterday. In between I updated Firefox from 76 to 77. Unfortunately, I need meet jitsi tomorrow and it must work tomorrow. So I don’t have time to test. If there is a problem, I need to know quickly what to check. That the reason why I ask without testing with Firefox 77, I expect the same problem will happen.

Just tell me if you need more information.

Thank you!

After more tests, the other person had two microphones on his computer and he choosed the wrong one. After changing the microphone, everything works without problems.

Sorry for this issue…