I don’t mind learning, and I’d like to learn. That’s why I’m here. I’ve found a helpful post - Matter over WiFi success story - enabled IP6 on Unifi network
I appreciate the details of things to look at. I’m going to continue with the current setup and see if I can get it working.
I’ve enabled IPv6 on my router, and I’ve checked my firewall rules are for both IPv4 and IPv6 in my router.
Side note: Matter isn’t my problem. It’s Thread. Wi-fi Matter devices are having no problems being in both Homekit and HA. If it’s a Matter over Thread device it fails.
I’m also not alone in this, and it might not be my network causing the problem. This is a more recent post - Matter over Thread network fell over | Ars OpenForum
Other info of note:
The Thread network (with the AppleTV Border Routers) show up in the thread integration in HA.
I now have a different error. So, I’m calling it progress and I’ll keep researching some of your suggestions!
2025-07-24 15:59:00.058 (MainThread) INFO [matter_server.server.device_controller] Starting Matter commissioning with code using Node ID 24.
2025-07-24 15:59:09.883 (Dummy-2) CHIP_ERROR [chip.native.EM] <<5 [E:17323i with Node: <0000000000000000, 0> S:0 M:77409637] (U) Msg Retransmission to 0:0000000000000000 failure (max retries:4)```