@maxmp it does work now, I would know if its using high res due to the light indicator at the usb dac or screen at my fiio brt7, I just need to do this Settings>audio>output>high-res output>usb dac>toggle "no dvc" on then back to off. just do that trick to xiaomi/poco MIUI 12 and up.
another is just restart the phone. if the toggling doesn't work.
no problems on my LG v60,
my samsung a30 and its locked at 24bit 192kHz.
for samsung there's a conflict built-in software, settings>sound and vibration>sound quality and effects> UHQ upscaler dolby atmos and you can't turn this off, it will always stay on one you go back to the page or refresh the menu.