Invisible circle stroke color in SKSpriteNode (iOS)

Question

I'm trying to paint the stroke color in black, but it doesn't appear any line...

This is how it's displayed in the iOS simulator:

BUT, if I run the same code in the Xcode playground, the circle is perfect

My scene code:

import SpriteKit

class GameScene: SKScene {

   override func didMoveToView(view: SKView) {
      /* Setup your scene here */
      self.backgroundColor = UIColor.whiteColor()
      let midcir = self.mainCircle()
      self.addChild(midcir)
  }

  func mainCircle()->SKSpriteNode{
    let node = SKSpriteNode()
    node.anchorPoint=CGPoint(x: 0.5, y: 0.5)


    let outsideNode = SKShapeNode(circleOfRadius: 127.5)
    let insideNode = SKShapeNode(circleOfRadius: 1)


    outsideNode.strokeColor = UIColor.blackColor()
    outsideNode.fillColor = UIColor.blueColor()
    outsideNode.lineWidth = 5

    insideNode.strokeColor = UIColor.clearColor()
    insideNode.fillColor = UIColor.clearColor()


    node.addChild(outsideNode)
    node.addChild(insideNode)

    node.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))

    return node
}

}

And the playground code, it's for OS X for live view incompatibilities (live view): It only changes the UIColor for NSColor

import XCPlayground
import Cocoa
import SpriteKit


var myView = SKView(frame: NSRect(x: 0, y: 0, width: 400, height: 400))
var myScene = SKScene(size: CGSize(width: 400, height: 400))
myScene.backgroundColor = NSColor.whiteColor()
myView.presentScene(myScene)

func maincircle()->SKSpriteNode{
    let node = SKSpriteNode()
    node.anchorPoint=CGPoint(x: 0.5, y: 0.5)



    let outsideNode = SKShapeNode(circleOfRadius: 127.5)
    let insideNode = SKShapeNode(circleOfRadius: 1)

    outsideNode.strokeColor = NSColor.blackColor()
    outsideNode.fillColor = NSColor.blueColor()
    outsideNode.lineWidth = 5

    insideNode.strokeColor = NSColor.clearColor()
    insideNode.fillColor = NSColor.clearColor()

    node.addChild(insideNode)
    node.addChild(outsideNode)
    node.position = CGPoint(x: 200, y: 200)


    return node
}


let node = maincircle()
myScene.addChild(node)


XCPShowView("MainCir", myView)

I don't know that is happening, I'll post the answer if I find it. Thank you!