Roon downsampling when casting from Qobuz while Qobuz direct casting does not

[Rugby (aka Daniel or Big Dan)]

Well, I would say that it is probably a Technics issue. See link below

Supported sample rate of Chromecast builtin

Roon only sends >48kHz audio to devices that declare the HI_RES_AUDIO_SUPPORTED flag via the Chromecast SDK. If your device doesn’t report this flag, it’s basically stating that it doesn’t handle anything over 48kHz. If your devices support >48kHz sample rates and don’t report this flag, there is a bug in their implementation of Chromecast.