AppleTV screen saver
Recently my screen saver on my AppleTV started having a pop up message about the ability to use AirPlay to view from other devices. It would be fine once but it keeps popping up. How do I turn it off?
Living Room
I think you may be referring to the Conference Room Display notification.
It has an On|Off switch in Settings﹥AirPlay and HomeKit﹥Conference Room Display﹥.