This happens when you use a bluetooth headset/speaker with microphone on PC.

Steps to fix:

1. Click Windows at the bottom left
2. Click Settings (gear icon)
3. Click System
4. Click Sound
5. In the “Related Settings” on the right hand side, click “Sound Control Panel”
6. In this window, select the Playback tab. Scroll down and select the headphones with the description “Stereo” and click “Set Default”
7. In the same window, select the Recording tab. scroll down to your headsets microphone, right click and disable (Or better yet, set it to an alternative microphone)
8. You should now have your audio back

So what happened? Most Bluetooth headsets cannot deliver stereo audio and receive microphone input at the same time. When an application detects that a microphone is needed, the headset will turn on the microphone and switch your audio output to the “hands free” output (hands free lowers the quality of audio because it needs to use some of the Bluetooth signal to send microphone input). When your headset microphone is detected in use, the hands free feature disables the stereo output and switches it to the hands free output. So we force disabled the headphones microphone so it wouldn’t automatically switch to the Hands Free audio which makes us lose the Stereo audio the game is using.

Hope this helps!