I pressed this button and it has now muted all of my voice comms and I cant hear anything on them. It really sucks.
I learned this the hard way. What that button does is keep the volume level of your "current channel" (the channel who's tab you are on) the same, but it sets the volume of all other channels to ZERO. So if you are on the platoon tab and hit "squelch other channels", it will leave your platoon receive volume the same, but will set proximity, squad etc to zero. Resolution: go tab by tab and manually reset the receive volume to 50 or whatever level you had it at previously.