Hi Sergio,
Assuming your audio is working on the client, there are two reasons why the listeners window may not be receiving updates.
1. The first is that BigBlueButton is unable to connect to FreeSWITCH on the server. You'll see the is if you enter
sudo bbb-conf --check
and it tells you that the SIP connection is not work. (I'm assuming here you have access to the BigBlueButton server). In this case, audio does not work.
2. There is a race condition when users join a session. It does not happen often, but when it does, one of the users locks the shared object that updates the listeners window. You'll get the initial data in the Listeners window (and the initial data may be empty if there is no users in the voice bridge when you join). But in this case, you get no future updates, but audio will work.
See
Regards,... Fred