It is possible it has to do with using FMOD in some way rather than the Unity version. Though I think Unity is internally using FMOD anyway. So I suspect it may be the Unity version, though I'm not 100% sure.
Viewing post in Gustavo's Nightmare jam comments
oh boy, it's so hard to pinpoint where the problem may be... haha.
I'm also using a USB audio interface but I have no issues.
I have a different problem though, I get extremely crackly audio when using Chrome (this happens with any WebGL build on itch.io) but my audio is completely fine in Firefox...
I know for sure FMOD and WebGL don't like to play nice and take a little more setup that I was unaware of when creating the original build that's currently up for Gustavo's Nightmare. I have Unity audio disabled in engine so I'm assuming it shouldn't have to do w/ Unity but I wouldn't completely rule it out yet...
This is all still a bit of a knowledge gap for me but I'm experimenting with different build settings and scouring forums to try and find some answers haha wish me luck!!