I am having slightly different issues related to sound:

The first one is that when I have a Discord voice chat in the background, it sometimes causes popping noises with the game audio.

The second one is that the game randomly loses right channel audio. Sometimes it comes back after a while. The can be fixed by restarting the game client. I have a similar issue with Firefox when watching Youtube videos.

I also had two occurrences of the sound completely stopping to work. Both time it was inside dungeons, but these were something like a year apart from each other.