Audio When built to mobile device, volume is being maxed no matter what

I have this extremely frustrating problem which I haven't been able to solve.

The project's settings "Global Volume" is set to 0.5, but this setting isn't being kept when we build the game to mobile devices. We did this because we found that changing the volumes of mixer channels/groups (ie. setting master channel to -10dB, or sfx channel to -10dB) does nothing. They just revert to default once the game is built (even in unity). So there ends up being loads of distortion because everything is being clipped. We created a new, empty scene, and the volume changes in the mixer groups DON'T revert to default. Something is clearly happening in our scene to affect this... but the programmers aren't sure what, and they haven't yet been able to find anything that is causing these changes in our game scenes.



In this screenshot above, samples 1 and 3 are taken from video recordings of the game off an iPad. There's clearly some normalization to 0dBFS going on, so there's lots of clipping and it sounds awful.

Sample 2 (in the middle) is just a unity recording. All the mixer groups are just set to the default of 0dB (because we found that changing them did nothing), but instead the "Global Volume" in the project settings is set to 0.5. That's the only way we've found to get the headroom we need to avoid mass distortion. The sounds have room to breathe and everything is sounding great. Unfortunately, that setting isn't being ported to the mobile builds.

Pretty confused with all of this. Would love some help.

Thanks