Muting players doesn't always work.
Whether I choose to mute a single player or mute all, I still hear people talking using the in-game voice chat. Sometimes it works but most of the time it doesn’t. It seems to be “random” as I haven’t figured out a way to reliably reproduce the problem, but it occurs more often than not.
Is this for a single game? I’m pretty sure when the map changes, anyone muted is no longer muted.
I can still hear people immediately after setting mute all on, or muting individual players. It shows the mute icon beside everyone’s name. And yes, changing maps resets anyone you have muted. Additionally, if I’m not mistaken, when people join the game they are not muted automatically if mute all is set. Not sure if that’s a bug but I figured I’d mention it anyway.