(Audio/CromeCast) Can't control audio outside the app

Hi,
since a while I can call myself a Google Audiocast owner :wink:
I’ve noticed that I can not control the Audiocast volume outside of Plex when I’m connected to it.

Is this mentioned to be like this?
I’d would be great to be able to control the volume outside the app too.

Device: Bacon (Android 6.0.1)
Plex V.: 5.4.0.715 (da9d687c)

Sooo, I’ve restarted my device some times since I posted. It seems that the audio focus of Android sometimes does not pick up the Plex app when it streams to the audiocast but sometimes it does. I will try to get some logs.