Before the update for Android 7, the Hi-Res Output was working (24-bit 192) version 703. After an update of Android and MIUI did not work anymore. I installed version 704 and it also did not work. Only OpenSL ES output works.
1 - Redmi Note 4X (Snapdragon 625)
2 - Android 7.0 / MIUI 8.5.4.0
3 - audio_policy.conf (attached)
audio_policy.conf