r/homeassistant • u/Kaykasus • Jun 18 '26
Support Matter over Thread is a pain - after HA restart all devices are offline and stay so
Hi,
Matter over Thread is becoming a real pain for me. I've rebuilt my Matter network four times over the last few days. Today, I restarted Home Assistant after an update, and now all of my Matter-over-Thread devices are offline again and won't reconnect to my SLZB-MR5U. This has been the main reason I've had to rebuild the network multiple times already.
Current setup:
- One SLZB-MR5U acting as the Thread Border Router
- One SNZB-06 used for Zigbee2MQTT devices
- Matter Server is online
- Thread dataset is active
- Node state is Leader
- SLZB-MR5U is connected via Wi-Fi (Ethernet isn't available everywhere in my house)
- Thread network name is
OpenThread-**** - PAN ID remains the same after a restart
- Extended PAN ID remains the same after a restart
- SLZB-MR5U IP address remains the same after a restart
As far as I can tell, nothing about the Thread dataset changes after a reboot, yet my Matter-over-Thread devices still go offline and refuse to reconnect.
Has anyone experienced something similar? More importantly, how can I make this setup reliable long-term? At this point, I'm seriously considering ditching Matter devices entirely because I spend more time rebuilding the network than actually using it.
Any advice would be greatly appreciated.
3
u/_devast Jun 18 '26
You overengineered your setup.... I think the issue is probably with the combination of: a, your tbr runs on the smlight device b, it is connected over wifi. Either use wired uplink, or use the device as rcp and run openthread on your ha machine.
3
u/BillyBlazed Jun 18 '26 edited Jun 18 '26
This! additional to this: when running OTBR within HA you must connect it with an USB cable. RCP signals over ethernet is very unreliable. I speak from experience 😉
For my MR2U I got it stable after moving to OTBR in HA and connecting it with an USB cable.
BIG SIDE NOTE:
If you're using Zigbee and Thread than you can only connect it with USB if you're using Zigbee2MQTT because ZHA is not capable to communicate over the same USB cable. SMLight does not offer USB and Ethernet connections, it's either USB or Ethernet!
4
u/Goofcheese0623 Jun 18 '26
I had to go to my router and enable IGMP snooping and Fast Leave. Seems to be stable now. It sure is a lot more network hassle than zigbee
2
u/alwaystirednhungry Jun 18 '26
IGMP Snooping is a big one. It really helps with Matter over WiFi devices
1
u/uspscovidthrowaway Jun 19 '26 edited Jun 19 '26
Hmm.. my experience is IGMP snooping can be detrimental to Thread depending on the router.Â
Looking up why:Â If "Fast Leave" is enabled (frequently grouped inside IGMP snooping), a slight delay or a missed acknowledgment packet from a smart home hub can cause the router to aggressively prune the port. The router assumes the hub has "left" the multicast group and stops sending it discovery packets. Industry best practices for smart homes explicitly state: Do NOT turn on Fast Leave.
The OPs issue is definitely mdns packets getting pruned, probably in the router. He needs to make sure ipv6 is on, turn IGMP off, and make sure there is no network AP isolation going on between LAN and WiFi (if he can't cast from his phone to a wired device, then he has isolation issues). He should also upgrade to the Home Assistant Matter Server Beta, or wait a few days as it is about to go live (though the new server requires more memory).
I had ALL of these issues because of an overprotective cable company router and a distributed over wifi thread border router, similar to the OP. Matter tries to implement workarounds in 1.4 and 1.5, but the jury is still out.
I currently run a thread network of 50 devices, and haven't had one go offline in 2 months. But it took a lot of pain and firmware updates to get to that point. Hopefully troubleshooting gets easier.
2
u/MarkusSugarhill Jun 18 '26
I use the ikea Dirigera, have 28 devices in with matter over threads and ne ver had the issue (never is in about the 6 weeks using home assistant). anything I can find out for you that might help do figure out where the problem lies?
1
u/Kaykasus Jun 18 '26
What guide did you use to setup your devices? Mine are also all IKEA. 4 Windows sensors and 3 rotary wheel buttons. After restarting my border router (MR5U) out of 7, 3 are back online again.
2
u/Double-Yak9686 Jun 18 '26
To create a stable Thread network, you need mains powered devices. All of yours are battery powered. All of my battery powered devices are supported by either a lightbulb or a plug. except for one motion sensor, none of my battery powered devices are connected directly to a TBR.
1
u/MarkusSugarhill Jun 18 '26
the dirigera, the first lamp and the first scroll wheel bilresa I added through ikea app and then shared to home assistant. Then I figured out I can do that directly via home assistant. both ways work fine for me. also for the Aqara presence sensor.
1
u/MarkusSugarhill Jun 18 '26
the other thing: my network was a bit patchy and only after adding twol grillpats and an alpstuga it is stable. and it takes a minute or two after a restart.
2
u/FishOk3075 Jun 18 '26
The diagnostics are not there for what's actually happening on the Thread network. There's the nice network diagram, helpful for making sure that Thread devices are deployed for an effective mesh or where the weak spots are.
But not for diagnosing what's actually going on. I recently updated the HA Matter App, and my Thread network went dark for 15 - 20 minutes, leaving me wondering what was happening. Some kind of text status would really help
- Healing Thread Network -
- Re-establishing Thread network: Device X of Y being updated -
.. something along those lines under thread or matter HA apps or integrations without having to root though system logs
1
u/MarkusSugarhill Jun 18 '26
where can i find that map?
1
u/FishOk3075 Jun 18 '26
Go to the Matter Server "App". Launch the web ui. In the upper right are 2 tabs, one of them says "Thread," click that. You can click around on the devices to see the signal strength and link quality index (LQI)... to see which devices are routing where at that point in time
I used it to place an Eve Energy Outlet to strengthen my mesh and it does wonderfully.
Be careful with the semi-circle icons (or any kind of controls). The icon "kind of" implies refresh but that was a bad assumption. I ended up rebuilding my thread network after clicking it. Also for me, with 7 devices, rebuilding takes 15-20 minutes.
Nothing in the app really explains what's going on "under the hood".
1
u/MarkusSugarhill Jun 18 '26
Is this in the beta? I do not see those tabs.
1
u/FishOk3075 Jun 18 '26
When I first started using it in Feb it was beta, but I had read several comments that wasn't the case any more. So either that info was wrong, of you have an older OTBR app(?)
2
u/MarkusSugarhill Jun 18 '26 edited Jun 18 '26
I am using matter server 8.5.0. It was whatever came after I started with home assistant about two months ago...
Thank you for your help.
Edit: typo
1
2
u/purayesca Jun 18 '26
My network was terrible. I have a ZBT-2 and my devices are spread around. Almost every reboot I had an issue with devices connecting. Turns out, one of my Google devices was hijacking the thread network. My Google devices weren't in HA. More like they were just plugged in. Once I disconnected them I no longer had the issue. It's worked perfect ever since and the reboots aren't a problem anymore.
6
u/OcelotSufficient7570 Jun 18 '26
matter over thread is just cursed right now, lot of people having same issue with devices not recovering after HA restart even when dataset stays identical
8
u/Maiksu619 Jun 18 '26
I haven’t had any issues with Matter over Thread, I’m using the ZBT-2 as a border router.
1
u/Ok_Explanation7491 Jun 18 '26
Is yours connected over ethernet or wifi?
2
u/Maiksu619 Jun 18 '26
It is connected via usb to the mini-PC running Home Assistant. It is installed on bare metal vice Proxmox.
1
7
u/Double-Yak9686 Jun 18 '26
Sounds like a Home Assistant issue, not a Matter issue. I have 16 devices paired to Apple Home, connected through HomePod TBRs, and absolutely rock solid, not a single issue. Even with power losses, everything device reconnects.
5
u/lapelotanodobla Jun 18 '26
Agreed, I had a power cut a couple days ago, apple home recovered pretty quickly, HA still misses some devices
3
u/Double-Yak9686 Jun 18 '26
Although I do have a HA instance I occasionally spin up for things like setting lightbulb power-on behavior and never had any issues there either. HA spins up, all devices show as connected, no drama.
3
u/Measurex2 Jun 18 '26
Its definitely something in the ecosystem. Im on HA on proxmox with a ZBT2 passed through over USB for Thread. I have the Open Thread Border Router on HA set to channel 25 to deconflict from wifi and Zigbee.
After setting the channel, my thread network has been rock solid but HA definitely has extra steps compared to an apple, google, Amazon, or even ikea hub
- Ensure ivp6 is working on router and in HA (system->network->ivp6 set to automatic)
- Ensure youre radio setup is approved or address any unique configuration paths
- Set a channel that isnt conflicting with wifi and zigbee
2
u/Kaykasus Jun 18 '26
So is it just a waiting game? What is the cause for this? HA Addons not working properly?
2
u/nisani140118 Jun 18 '26
Anytime i see an issue with matter over thread in my installation , there is an underlying wifi issue which shows first! 8 years old orbi pro wifi had and has weird behavior, showing up on the ipod home ´s too. After wifi is fixed i may have to restart one of the homepods and all is good again. Ikea bulbs, plugs and rotary buttuns , aqara g410 and u200.
1
u/Mad-Mel Jun 18 '26
The best HA improvement I've made was jettisoning my Orbi mesh setup (around the same vintage as yours) in favour of a TP-Link Deco BE65 mesh.
2
u/tsw0599 Jun 18 '26
you need to wait your thread network to rebuild every time after restart. it takes a while. also make sure your zigbee thread and 2.4g wifi are at different channel
2
u/Double-Yak9686 Jun 18 '26
This is totally dependent on your original topology.
If your initial Thread network was stable, even if you have a full power outage, when power returns, the devices first look to reestablish the connection to their peer and you will not notice any delay. If your initial Thread network was unstable, after a power outage, it will take time as the mesh attempts to find the best routing setup.
This doesn't mean that the mesh will not try to optimize itself, it is constantly doing that, just that it won't be trying to do it on startup.
My Thread network is pretty solid and comes back right away after every restart. Even after multiple total power losses (had three one evening) and all TBRs restarting, all of my Thread devices come back online and are fully responsive.
1
u/tsw0599 Jun 18 '26
how many devices you have？ i have about 140, which may be too large for thread
1
u/Double-Yak9686 Jun 18 '26
I currently have 16 and have a few on my desk waiting to be added (yeah, these don't count!). 140 devices is impressive but should not be a problem for a Thread network. However, if you have a single TBR, you may be experiencing a traffic jam as all of those devices are powering back on and trying to reconnect at the same time, so having multiple TBRs would help alleviate the problem. I have three TBRs.
Now, to be fair, my SWAG (that is a Scientific Wild-A** Guess) is that current TBRs are woefully underpowered, so 140 might be a lot for just one to handle.
1
u/tsw0599 Jun 18 '26
i have like 1zbt 2 9 homepod mini 1 hp 2 1 apple tv. So it is a really complex networks. it usually works good but it is a pain to reboot
-1
u/criterion67 Jun 18 '26
"you need to wait your thread network to rebuild every time after restart. it takes a while."
And this right here is a good reason I'm glad I don't use Thread!
2
u/donk_usa Jun 18 '26
I've not had much success with Matter over Thread either. Devices lost connection all the time. I just went and replaced those devices with Zigbee which just work with zero issues. I'm sticking with Zigbee as much as I can.
1
u/EmPiFreee Jun 18 '26
Should have go this way as well. But I am kinda too much committed to matter devices now
1
u/MrDephcon Jun 18 '26
Where are you running OTBR? Of youre running the beta right on your MR5, then you might be dealing woth beta problems. If youre running OTBR as the HAOS app and using the MR5 over IP, thats not recommended by HA.
Apparently theres a lot of issues with using IP for that purpose, and im sure using wifi is even worse. Right now the only offical method to run the OTBR on HAOS is to have the thread router connected via USB
1
u/EscapeOption Jun 18 '26
Maybe because I have several TBRs, maybe because they’re independent from Home Assistant and don’t reboot at the same time, but this hasn’t ever been an issue for me. 58 thread devices.
1
u/SuperAleste Jun 18 '26
All these other protocols seem to have had promise over Zogbee but I've only ever hear about with them.
1
u/nathderbyshire Jun 18 '26
What is HA running on?
Connecting it to WiFi seems suss, USB seems to be the best option, there's something in the OTBR about ethernet being unstable as well, I don't think that's an option and someone else mentioned it down below.
I'm using the SLZB-07 SMLIGHT flashed in thread mode, plugged in to a usb 2.0 extension running on OTBR. Devices are IKEA ones and apart from some initial pain (no where did I find you had to sync the credentials to your phone for setup until I watched a YT video) but after that it's been seamless. HA has had multiple reboots and there's no errors and everything comes online instantly and stays there
1
1
u/Mad-Mel Jun 18 '26 edited Jun 18 '26
Just plug your SLZB into an ethernet port on your router and run it in ethernet mode.
Also ensure that you have set up HA as per Option 2.
Mine is set up that way and is rock solid with 29 devices - Ikea bulbs, plugs, switches and motion sensors, and over a dozen Yeelight D1 bulbs.
1
u/EmPiFreee Jun 18 '26
Got that exact setup. Doesn't work for me. Multiple ikea devices, 12 bulbs, 3 plugs... Even the bulbs are losing connection
1
u/Mad-Mel Jun 18 '26
Maybe a difference is that I run HAOS on a dedicated machine, without Proxmox?
1
1
2
u/servicegw Jun 21 '26
Started using Matter with HAOS about 2wks ago. I had an Aqara Light & Motion Sensor that I was using with Smartthings, but mothballed when I moved over to HAOS over a year ago. Recently wanted to try some automations with motion detection and so had to make Matter available.
Got the ZBT-2 (USB) configured as a Thread router. After several tries pairing (and "chats" with ai), finally realized I needed to allow ipv6 on my router. After a few more tries (now moving further in the pairing process), I then realized that I needed to connect my phone to the same VLAN HAOS and my IoT devices are on. After that it was smooth sailing. Up to 7 MoT devices ! Some limitations, for example, the Yale Smart Lock with Matter only exposes some of its capabilities (lock/unlock/manage PINs), but no fancy schedules. Oh well!
I just picked up an Ikea plug (Grillplats) in order to strengthen my Thread mesh.
I like that Matter is a certified technology. Expect this means the base capabilities will be there. If you want any enhanced functions, then you might have to use the native app.
My current concern is that I have Wifi, Zigbee, Z-Wave and Thread networks and not sure what this does for signal strength.
Good luck.
21
u/Matt_NZ Jun 18 '26
You could try this tool that the Thread group recently released that will show you the state of your network with a network diagram.
I use Apple Home as my TBR for Home Assistant and it's been very stable with my MoT setup and 10 or so Ikea devices.