Thread / Matter issue with Nuki Smart Lock and Home Assistant (OTBR active but can't add devices)

Configuration Matter/Thread
1

Hey everyone,
I’m dealing with a persistent Matter over Thread issue in Home Assistant, and I’ve already exhausted most of the basic fixes.
I’m not a newbie – I’ve been working with HA, ZigBee, and Thread for a while, but this one’s strange.

:wrench: Setup

Home Assistant OS 16.x

Latest Matter Server Add-on

OpenThread Border Router Add-on active

USB sticks for both Thread and ZigBee (recognized and working)

Thread network: ha-thread-d2ee

ot-ctl state → leader

Matter server logs show normal CHIP activity (no critical errors)

:jigsaw: The issue

Whenever I try to add a Matter device (Nuki Smart Lock via Thread), I keep getting:

“Your device requires a Thread Border Router.
Please connect your Border Router and try setting up your device again.”

Thread itself is working — network is visible, OTBR is active — but the Matter Server doesn’t seem to recognize or fetch the Thread dataset properly.
In the Thread app, the HA Thread network is visible (ha-thread-d2ee), but when I try to send credentials to Home Assistant, I get:

“You don’t have any credentials to import.”

:mag: Already tried

Restarted both OTBR and Matter Server add-ons

Exported and manually imported Thread dataset

Checked IPv6 configuration

Verified Matter Server logs (no ThreadStackMgr interface found)

Used chip-tool to push dataset manually

Rebooted HA and phone, cleared app cache

Re-synced network in Thread app

:question:Question

Has anyone found a working way to sync the OTBR dataset to the Matter Server properly?
Or any idea why Matter Server doesn’t recognize the otbr0 interface even though OTBR is active?

It feels like a dataset-binding or internal API issue between the OTBR and Matter container rather than a network or hardware issue.

2

What’s actually supposed to happen is that the OTBR has to sync its credentials with HA, and with the HA companion app on your phone. The Matter Server get the credentials from HA when commissioning begins (in an advanced procedure, you can provide the credentials manually instead of using the app).

First, your Thread Integration settings should look something like the screenshot in the docs. The important parts are that you have (a) a preferred network with at least one border router, (b) it has an (i) icon in the upper right (meaning HA has the credentials) and (c) it has the key-in-a-box icon beside a router (meaning the credentials are being made available to the app — and you would be correct in noting this is not documented anywhere in the Thread docs).

All three are required if you want to use the companion app for commissioning — are any of them missing?

Also, which companion app are you using to sync credentials (iOS or Android)? The iOS app has some Thread troubleshooting options; I’m unsure about Android.

3

I tried setting up Matter on my Nuki Smart Lock today, but I kept getting a “can’t connect to network” error (Thread network). Please let me know if you have a solution.

4

I’ll take a guess … that you are probably either giving the device the wrong Thread credentials, or it is out-of-range to a nearby Thread neighbor…

5

Today I updated the OpenThread Border Router, and after that my smart lock was successfully integrated into Home Assistant.