EcoDim.07 Z-wave Dimmer -- no dimmer functionality in HA?

I added several EcoDim.07 Z-Wave dimmers to my HA instance (version 2024.2.2 in Docker container). I can switch on/off the light and also set the brightness level when the light is switched on but I can’t increase/decrease brightness from HA while the light is on.

Q: How can I access the dimmer functionality?

The dimmer has been added to HA via Z-Wave JS integration. I run separately the Z-Wave JS UI Docker container. In the latter I can see (and use) the EcoDim.07 dimmer.

Anyone an idea how to solve this?