It should be equal if they’re paired.
First you haven’t said if you’ve set up Home Theatre with your HomePods.To do that you need to update all software, on ATV, HomePods & the iOS device used to set them up. Instructions are here: Set up home theater audio with HomePod and Apple TV 4K - Apple Support
This cannot be used with HomePod minis.
You don’t need to use this new feature. If you don’t want to use it go into ATV Settings - Audio and choose your TV Speakers as the default Audio.
If you were using it can you test turning it off by using tv speakers, then test HomePods.
We can help you further once you tell us what set up you are using. which HomePods & software you are on.
Regardless, still get all the software updates done. Restart Apple TV. Then test again .