the problam is that, the new light automatically go to light mix "rest", and not with yor name on the light mix, you canĀ“t control this light independent.
unless you do "generate". its great if exist an option to activate the "automaticallty go to light mix" the scene lights, with your names to control independetly.
Sometimes I forget to generate and then at the end of the render I can't control it independently.
On Vray when you create a new light you dont need to generate light mix, it go to light mix automatically.