Rooms are disappearing from HomeKit

See if you can delete the default room. Move the devices to the correct rooms first. Try renaming it first and click done. Then go back and remove. It might not have an option to remove until you rename it and save its new name by clicking done.

Go to default room - top corner three dots - room settings

See if this helps to stop things moving to it.

You didn’t mention having any HomePods or it might be easier to reset or restart them.

The other thing left to ask is if you Upgraded to the new Home architecture? If not, you might try it out, just be aware any devices not running the latest software won’t be able to view the Home App on that device. This also applies to others you share the home with.

Currently your hub is the ATV and possibly the iPad depending on its model & OS it’s on. The new architecture does stop iPad from being a hub The issue is this default room. I deleted mine but it came back and tells me I have a HomePod not responding but there is no HomePod in it. Fortunately not moving my devices into it.

The only other option is to delete the entire home and set it up from scratch again. You can also get in touch with Apple to see if they can assist : Official Apple Support

Try resetting Homekit on Apple TV to see if it can fix it.

on Apple TV in settings - users & accounts - sign out of iCloud

restart Apple TV and sign back in

in HomeKit & AirPlay - set that back up by assigning Apple TV to desired room.

Going forward make sure all Apple devices are signed in and using the same Primary/default Apple ID and connected to the same wifi network. Keychain and Bluetooth also needs to be enabled on your iPhone (the iPhone you use to set up Apple TV)

If you have another Apple TV repeat these steps

Then it might be the accessories you have set up in the rooms. You might need to edit those and check there isn’t a mismatch

You can call the 1-800 number at the bottom of this page if you’re in n . America and ask to speak to an advisor about Apple TV, if this is your only hub, or if someone can help with the home app.

In my case it is shown on iPad, devices in it work but are not shown on iPhone. So it is an iOS issue. Device is fine.