Ubisys S2 device and "Could not initialize this Zigbee device"

I have a number of Ubisys Zigbee devices in my Homey Pro 2023. Today suddenly several of them are showing red exclamation mark sign on the device and when I try to use the devices, Homey says “Could not initialize this Zigbee device”. I have no idea what this error message refers to.

Some facts:

  • When I go to Homey dev tools, all these devices look normal in the Nodes table and they respond to ping
  • For devices that have two outputs, one output is working fine, and one output is broken

First I tried “repair” but it didn’t seem to do anything. I had to completely factory reset the devices, remove them from Homey and re-add them. And obviously had to also add them to all the flows again. A bit annoying.

Does anyone know what the error message means? Is it Homey or app issue or the devices themselves?