Cannot use HomePod as a standalone speaker after setting up as Home Theatre output for Apple TV

Set up a HomePod mini as the default audio output for my bedroom TV. Works brilliantly, and has vastly improved the TV audio.

However, I can no longer play music/audio through the HomePod without the TV turning on. The airplay option is a combination of Apple TV + HomePod. Since pairing them, they no longer appear separately.

I can AirPlay music to the pair and the TV turns on (not desired). Turning off the TV unfortunately results in pausing the audio from the HomePod.

I would love the two devices to be displayed in AirPlay menus separately. I.e. choose HomePod (only audio goes to only HomePod) or Apple TV (AV will go to both devices).

Am I missing something?