HomeKit Device "No unpaired devices could be found"

Unfortunately I couldn’t find a solution to this. I’m coming from Apple Home with Matter, Thread and Zigbee device paired successfully in Home. Where possible I upgraded devices to Matter and reconnected them.

Now I’m in the process to migrate all my devices into HA but failed to pair the old HomeKit only devices. From what I understood, HomeKit Device is used to get a Homekit device into HA and HomeKit Bridge to expose it to again to my Home Apple home.

So I followed the steps to have the device

  1. first paired in Apple Home to have it in the network.
  2. Next I removed the device from Apple Home and did not reset it, so it stays in the network.
  3. I checked that it is still reachable if I try to reconnect it to Apple Home it pops up immediately and if I want I could easily add it again to home.
  4. Without reconnecting it to Apple Home I open my HA and tried to integrate it there. Opening Integration → Apple → HomeKit Device I just see “No unpaired devices could be found”.

I tried it with Eve Room battery device as well as with an old Eve Energy plug that can’t be updated to matter (old HW).

My HW is the Nabu Casa Home Assistant Green device without any additional HW USB dongle. Honestly I’m not sure when it is required to use the HA Connect ZBT-1 Zigbee Thread Matter USB Stick but I ordered it. How do I know what is required to connect an old HomeKit only device?