Homey Pro (2026): Zigbee and Thread suddenly can’t send, works 1–2 min after boot, then stops

Questions & Help
1

Hi all,

Since today (5 Nov) around 15:20 CET my Homey Pro (2026), firmware 13.5.3, can barely transmit on Zigbee or Thread. Everything had been running fine for weeks.

Symptoms

  • Almost all commands from Homey to Zigbee devices (IKEA, Sonoff, Eglo, Sunricher, Philips) and to Matter-over-Thread devices (IKEA GRILLPLATS/KAJPLATS etc.) time out or fail with “device unreachable”. This includes a Thread plug 2 m from Homey.
  • Incoming traffic partly works: sensor reports and Hue dimmer presses still arrive, but commands back out do not.
  • Right after every boot, things work for 1–2 minutes, then stop. After that only short random windows where a few commands get through.
  • Zigbee and Thread both report “ready”, no errors. Z-Wave is fine.
  • The Homey process shows high CPU (often 50–90%) and memory going 600–700 MB.

What I’ve tried (no change)

  • Reboot, cold boot (unplugged 30 s), and cutting power to the whole house via the main breaker (twice)
  • Router reboot; 2.4 GHz Wi-Fi locked to channel 1 (Zigbee/Thread are on channel 20)
  • Running Homey without Ethernet
  • Disabling my own apps, the IKEA app, and the flows changed today
  • Unplugging the devices added today (an IKEA GRILLPLATS and a Telldus Z-Wave plug), removing 8 IKEA GU10 bulbs, and pulling the batteries from the Hue dimmers I used when it started
  • Unplugging all 4 Google Nest Hubs (they have their own Thread network)

I tested once with Homey moved to another room. Zigbee seemed to work there, but it may just have been the window right after boot.

Setup: ~76 Zigbee nodes, 69 Matter/Thread nodes (mostly IKEA), a few Z-Wave devices.

Has anyone seen this? Any idea what could make Zigbee and Thread stop transmitting at the same time, and keep failing through full power cycles? A support ticket with a diagnostic report has been sent to Athom.

Thanks!

2

Hi.
Well the thread and zigbee is using the same chip, so it could be failing.
But try this app to check your thread/zigbee.

I guess you have checked that the homey is fully online, and you can e.g ping it and access it and so on?

Connecting using wifi/ethernet, or maybe both at the same time?
For me i could not use wifi and ethernet at the same time

3

Definitely open a ticket with Athom support!
You will most likely learn from them, that your network is at fault. But you never know if they didn´t change “support” strategy unless you try.

4

By the way, what’s your ip range/subnet?
They (athom/Lg) did some change to it in latest fw