Shelly RGBW2 white channel brightness


After reading anything I could find on google, need to ask the question “out loud”.

I use HA for integrating my smart home devices with Apple HomeKit.
Everything works like a charm except the Shelly RGBW2 integration.

I’m able to add it, I’m able to see it in HomeKit but I can only control the brightness when the RGB are on, I can’t control the brightness level of the white channel … from the Shelly interface it’s working but not from HomeKit …

Any ideas what could I do ?