How can I customize different volumes for each HomePod?

I have 3 homepods in separate rooms each. One room is much smaller so I like to set the volume of that one at half volume of the other two. I set up a custom scene where it would always reset the volumes to this specific setting at the end of the day in case I change volumes and I won't get startled if I forget to set it back.

This worked fine until about a couple of weeks ago. I realized that my one homepod is always the same volume as the others and there doesn't seem to be any option to customize it anymore. Is this no longer an option and is there a workaround?

[Re-Titled by Moderator]