I’ve been running into issues since a few weeks, where I cannot add any Zigbee devices anymore. It started with IKEA Tradfri which wasn’t responding anymore, and later other devices followed. I tried removing and adding them again, but it could find the device, but took too long to add them and failed. I tried a network reset, but the problem persists and devices (tried with Hue and iCasa) could not be added.
I also checked the channel, where all WiFi networks (Channel 1) in the area aren’t overlapping with the Zigbee channel(tried 16 and 21).
How are you trying to add devices to Homey? Are you using the IKEA Tradfri-app that connects your devices directly to Homey or are you using IKEA Tradfri Gateway-app.
When I was at 50-ish Zigbeedevices the entire network began to timeout and I had all kinds of issues. So I added devices to Tradfri gateway and Hue Bridge.
I’ve been in contact with Homey support and apparently somehow Zigbee was not responding at all anymore after the reset. A factory reset(luckily there’s an option to keep the data) was needed and now Zigbee is responding again as it should.