Openhab 3.3 stable : Millheat binding only reads values, cannot set them

I am trying to use the millheat binding in version openhab 3.3 stable to control an independent heater. I am able to get the bridge up and running, and I can find the heater via auto-discovery (for some reason textual definition of the heater does NOT work, but that is a different issue).

Once I have the heater thing, all expected channels are present. I can add items to all of the channels, and these do reflect the current settings of the heater, target temp shows the set temperature, heating state is accurate, master switch is accurate.

The issue I have is that I cannot control these values from openhab. Any time I change a value/state nothing happens, and the changes are eventually overwritten at the next update interval.

Has anyone else experienced this? It’s as if the binding can only read values, not set them, or that the app or cloud is immediately overwriting the set values. Perhaps there is something I am missing?

Here the same. 2 Millheat heaters