Client loses sound randomly

[Riardon]

My audio setup is 2.1 desktop speakers which I use most of time. They are set as default output device in playback devices.
I also have a headset which is new. I use it mostly during the night. When I plug the headset I set it as the default playback device in playback devices menu.
Most of the time I'm with the 2.1 speakers which are my primary audio output device.
I have open XIV and Firefox. Only these 2 nothing else. Suddenly XIV loses sound and goes mute. If I restart it then sound is back. Firefox keeps playing audio from videos. Music still goes on. So it's not like sound dies system wide. It's only XIV that does this.
Some other times it's only XIV that runs. And while in game in a dungeon sound stops. Just like that.
The whole thing is kinda random so I don't know what causes this.
Sometimes it happens when I alt+tab between browser and the game and sometimes while in game.
Same issue I had with my older PC since 2.0 launched. It's an old issue. I just took it on the forums now because it happens more frequently than before but it's still the same issue as I described.