Doesn't record scene correctly for Hombli Smart Bulb lights?

I have a problem with the Scene editor where it doesn’t keep the state of my Hombli Smart bulbs. I want a scene with color x,y and a scene with white light.
I have 3 lights in my living. The 2 hombli bulbs loose their scene configuration again and again - it defaults to white, while the BlitzWolf ceiling light, does apply the scenes as expected / can switch?
What am I doing wrong? Or is it a bug?