Can read data from Zigbee thermostat, but not update target temparature

I’m new to HA and my initial goal was to control a Zigbee thermostat and change the temperature during day/night. I was able to connect it and HA shows me the temperature that is currently set on the thermostat. But whenever I try to change the temperature in HA, it doesn’t update the thermostat.
What am I missing?

Here’s what I’ve done:

  • Installed HA on a Raspberry Pi 3B
  • Connected a Sonoff Zigbee 3.0 USB Dongle Plus and installed Zigbee Home Automation (ZHA)
  • Paired my thermostat with ZHA (Hama Smart Radiotor Thermostat)
  • Changed the temparature at the thermostat: HA shows the updated temperature
  • Tried to change the temperature in the HA dashboard, but it doesn’t do anything. It goes back to the last temparture when reloaded
  • Tried the climate.set_temperature from developer tools. It shows success, but doesn’t do anything
  • Installed Log Viewer to see if I can find any details, but I don’t find any errors in logs

What else can I try? Is it simply not possible or is there a hardware incompatibility? How would I find a thermostat that I can be sure works?

You may want to check out the following Community Guides:

Thanks @Didgeridrew for the links. I realize Zigbee may not be the easiest network to set up and switching to Wifi would be an alternative (with its own downsides). But what I have at the moment is a Zigbee thermostat and I don’t want to give up just yet.
My issue is quite specific: The devices are connected and I can read the sensor data from the thermostat. Parts of the Zigbee network seems to be working. But when I try to change the temperature, HA makes it look like it worked (success message and no error in logs), but it doesn’t.

So I was hoping to find someone who had a similar problem or similar hardware who could point me towards what else I could do to troubleshoot this.

I was not trying to dissuade you from using Zigbee, I have about 50 Zigbee devices myself. My purpose was to point out how important a strong mesh is. Though it was a different type, make, and model, I had a similar issue with my thermostat when I first started using Zigbee. The solution came down to adding enough router devices to form a strong mesh.

That’s interesting. My plan is to add more devices in the future, but I wanted to get the basics set up without too much initial investment and then grow the number of devices.