24 Bit/192 kHz availability

I’m using the Lightning to USB cable with my Dragonfly Cobalt DAC. Regardless of what I do, it always shows a green LED for “high res” music playing in the Music app. On this device, Green means 44.1/16. Amazon Music HD has no trouble making the LED turn blue (48khz) or light blue (96khz).

I’ve got an iPhone 12 Pro Max running iOS 14.6. I’ve enabled High-Resolution Lossless in Settings. I downloaded several albums that Music reports as high res. I’ve also deleted some albums I already had downloaded, and re-downloaded them again in high res. None of it made a difference. All albums play at 44.1khz according to the Dragonfly Cobalt, a well regarded USB DAC known for working very well with iOS.

Conclusion: Apple High Res isn’t actually available yet, despite what Apple says, because the high res part of the content can only be listened to using a USB DAC, and as posted above, the Music app forces the DAC to 44.1khz.

See the 'Frequently asked questions about lossless' section in:

About lossless audio in Apple Music - Apple Support

Can I listen to lossless audio using Apple’s Lightning to 3.5 mm Headphone Jack Adapter?

Yes. The Lightning to 3.5 mm Headphone Jack Adapter is designed to transmit audio from the iPhone’s Lightning connector. It contains a digital-to-analog converter that supports up to 24-bit/48 kHz lossless audio.