You can import everything into Apple Paaswords on the Mac.

There is a specific set of columns you need in a .csv file.

Love to test for you

I’ve had similar issues in the past.

You can restart the HomePods and your AppleTV should become the hub.

It should stay the hub until you restart or have a power outage.

IMO the hub should prioritize anything with a wired internet connection Apple TVs then HomePods last.