Chromecast media player shows erroneous status

I recently observed that the built-in Chromecast of my Nvidia Shield sometimes shows “Plays Music”. It appears randomly, while nothing is playing on this device, and often a few hours after the device has been idle. It’s all the more strange because I almost never listen to music on this device…
Any idea why the Chromecast reports an incorrect status ?

Capture d’écran (19)
Capture d’écran (20)