iHome plugs have suddenly started showing up in Home as “Not Responding”

I have 5 plugs. The two KoGeek plugs continue to work in the Home app. The 3 iHome isp6 plugs suddenly stopped working in the Home app a few days ago. They are on the network and continue to work in the “iHome Control” app via my iPhone. However they no longer work in the Home app where they show up as “Not Responding”. They have been working fine since initial set-up 5 months go. If I restart the AirPort Extreme they show up in Home momentarily and work but within a few minutes return to the Not Responding Status.

As a test I removed one of the plugs from the Home app and did a factory reset on the plug. I then re-added via “iHome Control” app. It showed up fine for a few minutes in the Apple Home app only to disappear again.

Set-up: AirPort Extreme, AppleTV as the hub and connected via ethernet to the AirPort. I typically access devices via an iPhone, iPads, all running the latest version of iOS 11.

Also, no HomeKit/Home category in Communities?