Light Sources Canceling Each Other Out in SKLightNode

Question

In my game, I have torches that I wish to provide light. The code is:

let light = SKLightNode();
light.position = CGPoint(x: 0, y: 0)
light.falloff = 3
light.zPosition = 2000
light.categoryBitMask = 0b0001
light.lightColor = .white
    
self.addChild(light)

For each of my sprites I want to be affected by the light, I do this:

sprite.lightingBitMask = 0b0001

It seems that some of my torches are actually canceling each other out like in the attached screenshot. I'm thinking that I don't understand how the fallout property works.