Can't hear anybody with Mumble

I am trying to get Mumble-VOIP to work on my server but for some reason it doesn’t work with talking to people nearby. You can’t hear them, and they can’t hear you. Also, your lips do not move. But for some reason the rp-radio works fine. You and the person you’re talking to can hear each other fine.

I made sure onesync is enabled by enabling it in the Zap-Hosting web panel, and I also added “onesync_enabled 1” in my server.cfg file. Mumble says “Normal” not “Initializing” so it looks like it should be working fine, but talking with somebody near you doesn’t work at all. Only the radio does.

Please help, thanks in advance.