Apple TV volume control during AirPlay
I am having inconsistent results with controlling the volume on my Apple TV during AirPlay from my iPhone 12 Pro. Here is my setup. My Apple TV outputs to a receiver via HDMI. The receiver is hooked up to play sound via speakers throughout my home and there is no display connected to the receiver. Also, the receiver and the Apple TV are both in the utility room in the basement so it is not possible for me to control the receiver volume or the Apple TV via IR remote without physically being present in the room, which is simply impractical. The volume on the receiver is set at a constant level.
I have noticed that when I initiate AirPlay from my phone to play on the Apple TV connected to the receiver, I am able to control the volume from my phone sometimes. However, other times I am not able to control the volume from my phone. It outputs the sound at a constant level.
I would like to be able to *consistently* control the volume using my phone. Any suggestions would be greatly appreciated.
Thank you.
Apple TV 4K, tvOS 16