I can't hear someone while I stream, but they can hear me

I tried streaming music videos to watch on my server. I had 2 viewers but I could only hear one of them. I told the inaudible one to call me and I could only hear them when I call them. I can see the indicator flashing green, but there's no audio (even though I put the User Volume up). I had to end up making 2 accounts (one to stream and the other to talk to them) and they had to use 2 accounts, as well (one to watch the stream and the other to talk to me). I deleted the voice channel I made and created a new one. What's wrong and how can I fix this issue?