UIViewController with ARSCNView takes significant time before presenting on screen

I have a UIViewController which uses ARSCNView and adding few elements to it via Scenekit as shown in below example. Everything is working fine except when I call present to show this view controller, it takes a significant time or delay before presenting on the screen.

@IBOutlet var sceneView: ARSCNView!

override func viewDidLoad() {
    super.viewDidLoad()

    sceneView.showsStatistics =  DebugSettings.isDebugActive

    for (index, coach) in coachPositions.enumerated() {
        let coachGeometry = SCNBox(width: 0.1, height: 0.1, length: 0.1, chamferRadius: 0.005)
        let coachNode = TrainEngineNode(position:  SCNVector3Make(0, Float(index) * 0.1, -0.5), geometry: coachGeometry)
        sceneView.scene.rootNode.addChildNode(coachNode)
    }

    self.sceneView.autoenablesDefaultLighting = true
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    // Create a session configuration
    let configuration = ARWorldTrackingConfiguration()

    // Run the view's session
    sceneView.session.run(configuration)
}