Yesterday I’ve added 2 zigbee devices however when I went to bed I noticed that Homey wasn’t turning off the lights. It gets a timeout. The next day I checked the developer tools and under tab Zigbee it shows all zigbee devices offline. I rebooted Homey several times, even left it unplugged for about an hour. I tried the full software update trick in DFU mode but homey just doesn’t seem to work. I also removed the added devices from homey. When I toggle lights the flows work and Homey states the device is on, however it isn’t. I also powered down zigbee devices but this doesn’t help either. I have so much issues with homey it is just getting unreliable. Is there any other option I can try before factory resetting? I have a early 2019 homey pro
If you are still using the original Homey power supply, you should replace it (5 V, min. 2.1 A).
Have you changed anything on your WLAN network? It’s possible that there is interference between the WLAN network (2.4 GHz channel) and Homey Zigbee channel.
To avoid interferences you have to fix the 2.4 GHz WLAN channel. On this webpage you can check if you have possible conflicts.
How many Zigbee devices do you have connected, including the new devices?
I have 30 zigbee devices. I checked the wifi and my wifi is fine. Nothing changed there or from my neighbours. I replaced the adapter for a 2.4A. Zigbee devices are still unreachable. Did a factory reset and used a back-up.
I tried to delete a device and repair it. That worked. Does this mean I have to do this for all devices now? Because I will say goodbye to homey for this. Have to remove all lamps etc which will take atleast a day of work. Might as well pair it with home assistant directly.
You didn’t have to do a factory reset.
The option above Factory reset in the setup menu will do:
“Download full software”
This solved similar zigbee issues for several users
Did not for me.
To Repair a Zigbee device doesn’t mean to delete it and add it again. Just try to add it again. If it works a message will appear “The device still exists” (or something similar).
But a “Full Software Download” should actually eliminate also such problems.
Therefore I would suggest to contact Athom or to say goodbye to Homey. 
This was my issue when many of my Zigbee devices suddently started misbehaving. I had my Wifi at auto for the channel selection, and at some point it suddently decided to change to a channal that interfered with the Zigbee network.
I had not thought of that, so thanks for the tip!
