Hey everyone,
Spent an evening (okay, a night 
) on this and could use a sanity check from people with more Thread experience.
Setup: Nuki Smart Lock Go (latest firmware), SLZB-06MU as OTBR (add-on / “Thread to remote OTBR” mode), Mosquitto on the same HA host (IPv4). Goal: run the lock on Thread only and get its MQTT events over Thread so I can turn Wi-Fi off for battery life.
What works:
- Matter over Thread - perfect, channel 25
- MQTT over Wi-Fi, works instantly
What doesn’t:
- MQTT over Thread (Wi-Fi off), fails with Nuki error 8E every time!
I went down the rabbit hole to rule out my own stack, and it all checks out:
nat64 state→ translator + prefixmanager both Active- NAT64 prefix shows up under Routes in
netdata show dns config→ server announced, Nat64Mode: allow- ping of the synthesized broker address from
ot-ctl→ 0% loss, so translation works nat64 mappingsafter an MQTT attempt → zero TCP packets toward the broker, only my test ping
So from what I can see, the lock isn’t even trying to open a connection over Thread – everything on the network side is healthy but nothing leaves the lock. Feels like a Nuki firmware limitation rather than a config issue, but I’d love to be proven wrong.
Anyone running MQTT-over-Thread on a Nuki (Go / Pro / Ultra) to an IPv4 broker successfully? Or hit the same wall? Curious whether it’s just me. Thanks!