Can't connect Bosch Radiator thermostat II [+M] to Homey Pro

I have just recently got my Homey and am a complete newbie. Most have worked fine thanks to all your posts :–) but I now I am trying to connect my Bosch Radiator thermostat II [+M] but Homey does not recognise it. The thermostat is Matter over tread. I have even tried to have the thermostat in pairing mode very close to the homey Pro with no result.

Does anyone have experience with this device or a clue why the device cannot be found by Homey?