eWeLink zigbee RGB bulb problem: not turning on to specified color

Hi all,

Recently I’ve purchased this eWeLink bulb code CK-BL702-AL-01(7009_Z102LG03-1) and now I have some issues with it.

One one hand, it’s very bright and colorful, which is great; however it has one quite annoying behaviour - it cannot be turned on to a specific color.
If I call service “light.turn_on” and define color and brightness, it will turn on but NOT to specified color, but the last used one. For some reason it seems that it cannot handle 2 commands at once?
So currently I’m using a workaround, first send a command ON followed by a service call to turn on with specified color. In this case at least I can get desired RGB value out of it.

Does anyone have a similar bulb, or a similar issue with another bulb?
Any suggestion on how to fix this?

Thanks in advance!