Bosch Thermostat II does not connect to Zigbee 3.0 gateway and SmartLife app - no pairing

Hi,
I have purchased a Bosch Thermostat II radiator thermostat for my flat. I want to control it via my phone.
To do this, I bought a Zigbee 3.0 gateway (which connects to the router via an Ethernet cable). I have the SmartLife app installed on my phone.
I have added the gateway in the app without any problems; however, I cannot add the thermostatic battery in any way.
The battery is in pairing mode (flashing orange), but the app does not detect it.
Can you please help me? What am I doing wrong?



.

Take a look at this
https://www.youtube.com/watch?v=kgsgwnrEYN8
looks like bosch has their own program and may have some kind of weird communication protocol....
Greetings. J.