Hello @jimmy_stabler,
As @Derek_Wyman mentioned, there have been some reported issues with hi-res chromecast playback and Google is aware of this fact but there have been no new updates recently. You can follow the main thread here (Chromecast Audio dropouts).
As for your question regarding Enhanced vs High Quality, I would need to see the Signal Path screenshots to make a conclusion regarding that question.
Thanks,
Noris