I was in an Altis Life server on ArmA 3.
I told someone my Direct Comms channel isn't working (That I can't hear or see anyone's Direct Comms but they can see my Direct Comms text messages) and the person told me that it didn't work for him until he got a mic.
I then closed ArmA 3, plugged in a random headset with a mic, re-joined the server and it worked. I could now see and hear other people's Direct Comms channel strangely enough.
It would be great if this issue was fixed, as some people don't have microphones but would still benefit from hearing/seeing the Direct Comms channel.
I have reproduced this problem once, as long as I don't have a mic plugged in, I can't hear or see Direct Comms.