Adding AnchorPoint to SKNode breaks SKScene positioning - ios

Question

I am trying to have my SKCameraNode start in the bottom left corner, and have my background anchored there as well. When I set the anchor point to CGPointZero, here is what my camera shows:
EDIT:
Interestingly, If I set my AnchorPoint to CGPoint(x:0.5, y:0.2), I get it mostly lined up. Does it have to do with the camera scale?
EDIT 2:
If I change my scene size, I can change where the background nodes show up. Usually they appear with their anchor point placed in the center of the screen, which implies the anchorPoint of the scene is in the center of the screen.
I am new to using the SKCameraNode, and so I am probably setting it's constraints incorrectly.
Here are my camera constraints: I don't have my player added yet, but I want to set my world up first before I add my player. Again I am trying to have everything anchored off CGPointZero.
//Camera Settings
func setCameraConstraints() {
guard let camera = camera else { return }
if let player = worldLayer.childNodeWithName("playerNode") as? EntityNode {
let zeroRange = SKRange(constantValue: 0.0)
let playerNode = player
let playerLocationConstraint = SKConstraint.distance(zeroRange, toNode: playerNode)
let scaledSize = CGSize(width: SKMViewSize!.width * camera.xScale, height: SKMViewSize!.height * camera.yScale)
let boardContentRect = worldFrame
let xInset = min((scaledSize.width / 2), boardContentRect.width / 2)
let yInset = min((scaledSize.height / 2), boardContentRect.height / 2)
let insetContentRect = boardContentRect.insetBy(dx: xInset, dy: yInset)
let xRange = SKRange(lowerLimit: insetContentRect.minX, upperLimit: insetContentRect.maxX)
let yRange = SKRange(lowerLimit: insetContentRect.minY, upperLimit: insetContentRect.maxY)
let levelEdgeConstraint = SKConstraint.positionX(xRange, y: yRange)
levelEdgeConstraint.referenceNode = worldLayer
camera.constraints = [playerLocationConstraint, levelEdgeConstraint]
}
}
I have been using a Udemy course to learn the SKCameraNode, and I have been trying to modify it.
Here is where I set the SKMViewSize:
convenience init(screenSize: CGSize, canvasSize: CGSize) {
self.init()
if (screenSize.height < screenSize.width) {
SKMViewSize = screenSize
}
else {
SKMViewSize = CGSize(width: screenSize.height, height: screenSize.width)
}
SKMSceneSize = canvasSize
SKMScale = (SKMViewSize!.height / SKMSceneSize!.height)
let scale:CGFloat = min( SKMSceneSize!.width/SKMViewSize!.width, SKMSceneSize!.height/SKMViewSize!.height )
SKMUIRect = CGRect(x: ((((SKMViewSize!.width * scale) - SKMSceneSize!.width) * 0.5) * -1.0), y: ((((SKMViewSize!.height * scale) - SKMSceneSize!.height) * 0.5) * -1.0), width: SKMViewSize!.width * scale, height: SKMViewSize!.height * scale)
}
How can I get both the camera to be constrained by my world, and have everything anchored to the CGPointZero?