Hi, when I play “hi-res” content on my DAP, it has the ability to display current sample rate of the media.
Fiio music, the one shipped by the constructor has this ability, but also qobuz and others …
Symfonium seems to set wrongly the sample rate or make a bad use of the hardware of the DAP, the hardware can play at 96khz sample rate, but the system sample rate differ from the media.
See video below, the sample rate is displayed at top right corner:
When you enable the hi res / preferer internal option you need to switch renderer or forcekill / restart the app.
(The prefer internal have no effect on wav in this case).
In all cases this is not the issue here the engine properly output 96khz the issue happens later.
It can be a system equalizer that trigger that, Symfonium always broadcast so that equalizers can intercept I can add a option to disable this. You can also try to enable the internal Equalizer inside Symfonium without enabling the sub components.
Your phone default output is capped and only allows hi res when offloading, something that Symfonium does not yet support as experimental too.