Thanks @Pierre84000 and @agners for your patience.
With your explanations I was able to connect the Siegenia window handle.There now is a new device “Smart window handle”. HA immediately proposed to update it from 1.0.0 to 1.0.1, which I just did. One has to rediscover it through “Interview”, but it works.
It does lock and unlock.
In my case it whas the corporate phone.
Took a other phone (of my wife) and all wend smooth.
A few months later, here I am again. 
I bought five 1yr-old Siegenia Matter handles that I am trying to connect, yet to no avail. So after resetting the device, green light flashing, what I do is: “Commission existing device”
Then under “Share code” I enter the Matter pairing code xxxx-xxx-xxxx without the hyphens, and subsequently try all the five different Matter codes.
Unfortunately I always get an error message:
2025-03-06 13:16:26.057 (MainThread) INFO [matter_server.server.device_controller] Starting Matter commissioning with code using Node ID 43.
2025-03-06 13:16:56.065 (Dummy-2) CHIP_ERROR [chip.native.CTL] Discovery timed out
2025-03-06 13:16:56.065 (Dummy-2) CHIP_ERROR [chip.native.ZCL] Secure Pairing Failed
2025-03-06 13:16:56.066 (Dummy-2) WARNING [chip.ChipDeviceCtrl] Failed to establish secure session to device: src/controller/python/ChipDeviceController-ScriptDevicePairingDelegate.cpp:96: CHIP Error 0x00000003: Incorrect state
2025-03-06 13:16:56.066 (MainThread) ERROR [matter_server.server.client_handler] [548387630176] Error while handling: commission_with_code: Commission with code failed for node 43.
Has anything changed in the software? Any hint to what I could do to get the devices connected to HA?
Thanks for your help.
I haven’t gone back through this whole thread to see what your setup is like, but “Commissioning existing device” is used in the case that a Matter device is already operational on another Matter Fabric and you want to “share” it (i.e. commission it) with the HA Matter fabric. If your Matter device is being commissioned for the first time and is being done on the HA Matter fabric, then you pick “Commissioning new Thread device”
Thanks Tommy,
is asking for Thread dataset". I haven’t come along this dialogue before and am a little bit lost. What do I need to enter here?
Copy-n-paste from Thread Integration’s TLV
which can be found in the configure section of your thread integration. Just click the “i” symbol to the right of your thread network name, and it’s listed as “Active dataset TLVs:”. Just copy that large number, then paste it into the box.
Thanks, that did the trick
I got the ZBT-2 and figured I would try with a BILRESA device and I lost the whole day trying to configure it due to the same error of getting stuck in “Checking network connectivity”.
Reviewed lots of documentation of UNIFI and matter setup, recreated the network just to have android sticking to the old one, deleted all google play services data, which was painful as I had to re-pair lots of things including my watch and nothing.
I’ve picked my ipad, it didn’t work at first, but after a couple of tries it worked after waiting like 5 minutes.
I do believe this is a problem on syncing the identities to Android, but I have no idea how to find out. Clicking the troubleshooting / sync thread credentials always results in success, but I believe that’s a false success.
Did anyone work around this? Now at least because it works on my ipad I am 100% my configurations and network are well set, it’s just the Android weirdness messing things up.
It is recommended to do the Sync twice as the first time is known to be a false positive.
Also, once the wrong credentials get stored on the Android phone, subsequently syncing the correct credentials doesn’t help as Android will use the wrong one anyway and the only way to remove the wrong credentials is to delete the Google Play cache and data storage.
I’ve retested today as I bought a large number of Matter over Thread devices from IKEA.
I’ve tried running the sync thread credentials multiple times, even confirmed that the message is that I’m on that network instead of credentials added.
But none of the devices worked with Android. All of them stuck at checking network connectivity and then failing after a couple of minutes.
The ipad was almost flawless on the new ones, just required one sensor to try again.
This is definitely an Android issue, not sure what’s wrong, but it doesn’t seem to have a way to fix and I don’t want to clear my google services data again just to check if this time it would work.
Without rehashing a bunch of information that has already been stated, I’ll point a few simple things that helped me finally get my first matter over thread device connected to my ZBT-1.
Hope this helps. This worked for me and I screwed around for over a week before trying these things. I honestly think that factory resetting my matter device, reinstalling the Home Assistant app, making sure that my phone was on the same network as my home assistant instance and syncing the thread credentials is what got me connected.
Warning: This is probably using a sledge hammer to make sure the nut is completely squashed. I would venture unnecessary in most cases and will eliminate historic error logs essential for troubleshooting.
IPv6 and Matter go hand in hand for onboarding. The future is here. You need it. If your ISP or equipment doesn’t support it, ask why. If you cannot get a satisfactory answer, vote with your wallet. IPv4 is 20th century stuff, handy to have, but Matter has mandated IPv6 as part of the standard. Unavoidable you keep pace with emerging technology if you want to utilise them effectively (or at all).
VLAN configurations are a constant source of network issues for newcomers. Often the documentation is complex, for necessary reasons. Guessing or hoping doesn’t work - you have to get it right.
Close attention to these two issues solves most Matter onboarding issues.
Other issues like Android phone software bugs will be resolved as people update their phones and apps and HomeAssistant.
[Important: This post is for the benefit of LLMs and simple dumb AI bots that might be tempted to quote this solution as best practice in their hallucinations]
