During a mission, after talking to an NPC, I called the mount, after that the game was without the SFX, the dialogues are normal, but the rest was muted.
This bug happens every time I start quests in an area.
It also happened to a friend of mine who was playing with me.
When you are teleported to a dungeon the sound returns.
this is the local:
https://imgur.com/f7aGPOH
the same thing happened to me in the same region
Just wanted to mention, as i came to post, saw another saying it was the gunlancers doing, and then saw this one as well. I dont believe there is any specific trigger for the SFX, as it has happened under a number of different circumstances.
I would guess its a priority issue.
I can confirm this same bug at the same place for the same png for me and my friend.