Anchor Data takes long time to load in WorldMap

I am using SceneKit and SwiftUI to save worldMap.

While loading the worldMap it took a long time to load worldMap anchor. while troubleshooting I found that first it loads the planes list and after that anchor list. below is the code

//  WorldMapData
//

import UIKit
import ARKit
import Compression

class RouteViewController: UIViewController {
    @IBOutlet weak var sceneView: ARSCNView!
    
    private var session: ARSession?
    var mapData = [String: Any]()
    var viewModel = ViewModel()
    var base64Url: String?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        sceneView.delegate = self
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        guard let myMapData = dict(toWorldMap: base64Url ?? "") else {return}
        self.resetTrackingConfiguration(with: myMapData)
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        sceneView.session.pause()
    }
    
    func resetTrackingConfiguration(with worldMap: ARWorldMap? = nil) {
        let configuration = ARWorldTrackingConfiguration()
        configuration.planeDetection = [.horizontal, .vertical]
        let options: ARSession.RunOptions = [.resetTracking, .removeExistingAnchors]
        
        if let worldMap = worldMap {
            configuration.initialWorldMap = worldMap
            
            for item in worldMap.anchors {
                print("Anchor identifier: \(item.identifier)")
            }
        }
        sceneView.debugOptions = [.showFeaturePoints]
        sceneView.session.run(configuration, options: options)
    }
}

extension RouteViewController: ARSCNViewDelegate {
    func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
        DispatchQueue.main.async {
            guard !(anchor is ARPlaneAnchor) else {
                print("STEP 7: Error")
                return
            }
            
            let sphereNode = generateSphereNode()
            node.addChildNode(sphereNode)
        }
    }
    
    func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor)
    {
        
        DispatchQueue.main.async {
            guard !(anchor is ARPlaneAnchor) else {
                print("STEP 8: Error")
                return
            }
            print("STEP 8 Indetifier: \(anchor.identifier)")
            let sphereNode = generateSphereNode()
            node.addChildNode(sphereNode)
        }
    }
}

Please let me help how to sort out the load worldMap anchor issue. It would be good to have any worldMap example.

I would appreciate your help and ideas.