Lights aren't independent

[Dog2puppy]

I was recently trying to learn how to use lights in my photos and found that adjusting light 1 equally adjusted light 2 and vice versa. Is this expected behavior? If it is, how can I control the 2 lights independently? 

[R C-R]

It is the intended behavior, although not the one some users expect:

The Lighting Effects filter simulates the effect of shining one or more light sources on the surface of an image, as if you printed it out & shined lights of various types on it. The properties of the surface (like its diffusion, specularity, shininess, & specular color) affect how light would be reflected from it. In addition, the ambient light level & its color simulates how light coming from the surrounding environment (like from an overcast sky or room lighting) would be reflected from the surface. 

Since there is only one (simulated) reflecting surface, adjusting any of those parameters affects all the (simulated) light reflected from it, regardless of which light source the light came from.

[lepr]

.

[John Rostron]

You could duplicate your image, then apply separate lights filters to each. Then you could blend then as you see fit.

John