I m trying to setup my first Matter over

[karmic cairn]

I have made some progress on my problem. I had already installed the Nanoleaf app and updated the bulb firmware because I saw this recommended elsewhere. However later I discovered I can join the bulb to the Threat network through the app. I tried to do this, and it said I needed to define a Thread network. But the app showed one right on the same screen! This was suspiciously like what HA was telling me.

I read a bunch of more docs and threads online and found nothing terribly useful. On a whim, I decided to disable the Thread network in Eero, wait a minute, then re-enable it. After that I was able to make the bulb join the Thread network via the Nanoleaf app.

I still can't pair the device to HA though, but at this point I think it's more an issue for the Matter channel than the Thread channel. I just thought it was worth sharing that somehow restarting my Thread network fixed this problem of claiming I didn't have any border routers. I don't know why.