1. Sony NW-A100TPS
2. Android 9.0 (firmware 1.00.06)
Also, the stock Music player app does support Hi-Res. Looking at the Audio Detection Log, I can kind of tell why it is the only one that does...
Device: SonyAudio Sony NW-A100Series icx1293_001 EVK [arm64-v8a, armeabi-v7a, armeabi]
FAILED to read=/vendor/etc/audio_output_policy.conf
FAILED to read=/vendor/etc/audio_io_policy.conf
FAILED to read=/system/etc/audio_policy.conf
FAILED to read=/vendor/etc/a