Did you mean that the bit depth displayed on the DAC was always 192 kHz?I edited my post above. Not chromecast issues but transcoding, for example in iOS devices wired to DACs. AMU used to automatically transcode every track to the max playback quality set on the device. That may have changed by now but I saw that a year or so ago.
I did not know that.
The FireTV AMU seems to upsample everything to 24/192, but I haven't heard that about iOS. (Maybe I just don't know.)
The AMU resolution display has been changed several times.
Also, I don't know if it is accurate or not, so we would need to check on the DAC side.