For years I have had my zigbee network functional with a ConBee2 zigbee coordinator in my home assistant box.
But this week, devices started to randomly drop off the zigbee network. I could re-pair them and get them in again. But yesterday, it suddenly dropped 24 devices… Sensors, buttons and lightbulbs seem to be the most common ones.
I’ve restarted the ZHA integration, restarted the docker container, even downgraded to 2026.8.3. Still the same.
I checked the Home-Assistant github repo issues and there are lots of issues regarding zigbee and dropped devices in the last 2-3 weeks.
Does anyone have any suggestions as to why this happened all of the sudden?
The zigbee network has been stable for years before this.
EDIT: At this time I have re-paired all the devices and will see if they start dropping off again.
I could be close to the limit, I have about 46 devices on the ConBee2. But it is a new problem, I would have thought this would be happening as soon as I started nearing the limit, not months after it.
Assuming my memory is good, the limit is 32 devices without any router. This means that you can have many more if some of the devices are routers. And even if you have a device acting as a router, it will only be able to handle the devices that can connect to it.
So for example, if you have 46 devices, and the router is not reachable by enough devices, you will hit the limit, and most likely losing devices.
The theoretical limit is 500 if I’m mistaken, but only in ideal conditions with enough routers. Not having enough CPU on the base machine, is another example where that bottleneck will not allow the Zigbee network to expand that much.
Thanks. All the plugs and bulbs are routers, so I have about 20 routers in the network, so that shouldn’t be an issue.
Indeed, and also, have you checked the CPU usage? Maybe it is heavily used? Otherwise, I have no other ideas at the moment
CPU usage on the server is about 5-10% (it does loads of other things too), so home assistant is not using much.
It’s hard to know for sure an update, a glitch, or cosmic rays (probably not but who knows) can cause issues at times. The only thing you can do is troubleshoot and try to find a fix.