Not everyone hear all speakers

I have issue,
A conference of 20 participants. Some of the participants hear speaker A, and the other part does not hear speaker A, but everyone hears speaker B.

Browsers: Chrome last version.

jitsi-meet 2.0.7287-1
jitsi-meet-prosody 1.0.6155-1
jitsi-meet-turnserver 1.0.6155-1
jitsi-meet-web 1.0.6155-1
jitsi-meet-web-config 1.0.6155-1
jitsi-videobridge2 2.1-681-g3544ed05-1

Try to gather browser console logs from the participants that do not hear during the meeting and share here.