Not sure what the deal is but the mute all doesn’t work and individually muting someone isn’t working either. Nothing like a laggy game filled with idiots blasting garbage through their mic the whole time. Thanks halo.
I’ve noticed this too when people appear to be in parties and go to game chat that they can not be muted. As of lately I’ve been playing with no audio since I get quite a bit of different languages chatting that refuse to accept the mute option.
A more forceful way of muting someone would be going to their gamercard (or profile if you prefer) and muting them there.
This just happens sometimes from what I hear and have experienced. I fixed mine by restarting the game. Doesn’t stop it from happening again though, such is the nature of glitches.