Quote Originally Posted by Oniji View Post
Please see this thread OP for a current workaround. As well as other things you can try if the workaround doesn't work for you:
https://forum.square-enix.com/ffxiv/...-Sound-Effects

Current Workaround
Doing the following has fixed this issue for a lot of people. It appears that after the Endwalker update, the audio device set for Combat sounds was either missing or set to a non-primary device. Switching the device to something else then back to the correct device forces the audio device to be updated correctly.
In Windows 10: Sound Settings > Sound > Advanced Sound Options "App volume and device preferences" > Find "Final Fantasy XIV" in the list and change the "Output" device (top entry) to anything other than what it is currently set to, then BACK to what it is intended to be to.
I've had the 'sound disappearing issue' since... as far as I can recall. Disconnecting headphone, connecting headphone, or simply out of the blue like you mention. I alt-tab for 5 minutes to check something, poof, it's gone. The workaround above has worked for me very consistently. Hopefully it eases your frustrations until they sort it out.