When connecting to a Linux server wuth ALSA installed, even though the audio has been muted on the server using "Mute audio on the server", users can still hear sound coming from the output device on the server-side.

The problem has been reproduced on Fedora 32 with Gnome 3.36 as the desktop environment.
 

A temporary workaround is to try lowering the volume for default sink (using pavucontrol for example).