Apple TV - HomePod - AirPlay

The Apple ecosystem is fantastic, except when it comes to the subject of this post. Let me explain my setup:

• Apple TV 4k - Connected to ASUS router via Ethernet
• Smart TV - Connected to Apple TV via HDMI cable (high quality)
• HomePod - Connected to ASUS router via WiFi

On the Apple TV I have selected the HomePod (via AirPlay) as the audio choice with TV (via HDMI) not selected.

When I put the Apple TV to sleep and then turn it back on, Apple TV uses TV (via HDMI) as the default, never enabling HomePod (via AirPlay), even when Music app is started. When I go into the Control Center and look at the audio settings it shows TV (via HDMI) only. I then go into the audio configuration and I only see TV (via HDMI) as an option but then after about 15 seconds I see HomePod (via AirPlay) as well. At this point, Apple TV does nothing with regard to changing the default to HomePod (via AirPlay). I have to select HomePod (via AirPlay) and then unselect TV (via HDMI).

Don't even suggest a home network issue as it is flawless.

I have tried all kinds of variations for configuration all without success.

My expectations:

• When the Apple TV is configured for HomePod (via AirPlay) as a default, it should always remain the default, even if the HomePod is powered off. Because HomePod (via AirPlay) is WiFi connected and TV (via HDMI) is hardwired, I expect Apple TV to begin to use TV (via HDMI) but when HomePod (via AirPlay) is discovered, then AppleTV should use HomePod (via AirPlay) and deselect TV (via HDMI).

What I really would prefer is to use both simultaneously. Obviously, TV (via HDMI) is in front of me but my HomePod (via AirPlay) is behind me. What I want to achieve a kind of surround sound feeling wherein the audio from my HomePod (via AirPlay) is a slightly higher volume than the TV (via HDMI) and when I adjust the volume from the remote, it is adjusted for both maintaining the differences in device volume.

And then there is YouTube but I won't go there.