So I've been getting an issue since last weekend that's happened to me twice where all of FFXIV's sound will completely cut out. Doing anything in the in-game sound menu has zero effect, the only thing that fixes it is relaunching the game.
It happened during duties, but not the same duty - I'm pretty sure once last weekend before patch 4.31 during an Extreme, and just now during Praetorium. FFXIV is the only application affected by this, every other program continues on just fine. It starts with what sounds like a pop and then cuts out.
I'm on Windows 10, and curiously I find that if I open my volume mixer after the audio cuts out that FFXIV's volume indicator appears as if there is a max volume sound constantly being played. If I mute or unmute FFXIV from there, the 'pop' I heard when the audio cut out repeats despite not being able to hear anything when it's unmuted.