Apple TV "Home Hub not connected" error

I can no longer use Apple TV (4th generation) as a home hub. All my automations currently cannot run.

When using the Home app on macOS, the existing Apple TV accessory shows a No Response status. Using the Home app on iOS, the existing Apple TV accessory shows a Needs Repair status.

I've followed Apple's setup instructions for enabling home hub on Apple TV (same network, same account, enable iCloud Keychain). I tried following the advice of this post https://discussions.apple.com/thread/250893419 (on Apple TV go to Settings > Users and Accounts > iCloud - sign out; restart; sign back in). Nothing is helping fix the issue.

Apple TV 4th generation A1625, tvOS 13.4.6