When playing music from Qobuz using Google CAST to Q Active, all is
well until you let the iOS device shut down its screen after the prescribed time set within the device settings. The music continues to play, but when you wake up the app, it has
forgotten that a CAST device is being used, and so lets you start playing music
via the phone in addition to that being played by Q Active. Pausing, skipping
tracks or selecting something new then does not apply to Q Active until it is
selected as a CAST device again!
This also happens with the Qobuz App when using the Google Chromecast Audio puck so, we can only conclude this is a problem with the Qobuz iOS App not managing connected CAST devices correctly.