Mar 12, 2019
Thank you for posting and welcome to the Community Forums! I'm sorry to hear that you're currently experiencing issues with your Lifestyle 600 but would love to help.
To confirm, does the audio return after a specified period of time, or does it remain silent? If the audio does remain silent, how do you initiate the audio playback again?
If the audio does not return at all, it may be an issue with the HDMI-CEC functionality between the devices. Try changing the HDMI-CEC setting of the control console between "On", "Alternative" or "Off" then determine if the issue goes away.
I would also recommend investigating the CEC functionality on your Apple TV itself within the general settings to compare your own results.
It may also be beneficial to perform a product reset on your Lifestyle 600 and Apple TV. This can be done by simply disconnecting the systems from power completely for 60 seconds, then reconnecting back to power to test again for results.
Andy B - Community Support