Help with setting up spatial sound

I'm trying to setup a simple rotation of a 3D sound around a listener in iOS 12.3.1 using the AVAudioFramework. The idea is to have a listener in the center, a sound at 10m distance form the listener, and then rotate the listener.

I can get the sound to play, but not as spatial sound. Can someone point me where the problem might be ?

Here is my code so far:

import UIKit import AVFoundation

class ViewController: UIViewController {

var engine: AVAudioEngine!
var player: AVAudioPlayerNode!
var environment: AVAudioEnvironmentNode!


private var currentYaw: Float = 0
private var rotationSpeed: Float = 50.0 / 60.0 // 50 degrees per second, divided by 60 to get per frame at 60Hz
private var timer: Timer?
 

override func viewDidLoad() {
    super.viewDidLoad()
    
    engine = AVAudioEngine()
    player = AVAudioPlayerNode()
    environment = AVAudioEnvironmentNode()
    
    guard let fileURL = Bundle.main.url(forResource: "hello", withExtension: "wav") else {
        fatalError("Could not find audio file!")
        
   
    }
    
    do {
        let audioFile = try AVAudioFile(forReading: fileURL)
        
        // Check the format of the audio file.
        print("File format: \(audioFile.fileFormat)")
        print("Processing format: \(audioFile.processingFormat)")
        

        engine.attach(player)
        engine.attach(environment)
        
        let stereoFormat = AVAudioFormat(standardFormatWithSampleRate: audioFile.fileFormat.sampleRate, channels: 2)!
        
        // Connect player to environment node and then to the main mixer using stereo format
        engine.connect(player, to: environment, format: stereoFormat)
        engine.connect(environment, to: engine.mainMixerNode, format: stereoFormat)
        
        // Set the rendering algorithm on the environment node
        environment.renderingAlgorithm = .HRTFHQ
        
        // Position the player at the centre
        if let positionalPlayer = player as? AVAudio3DMixing {
            positionalPlayer.position = AVAudio3DPoint(x: 0, y: 0, z: 0)
        }
        
        // Position the sound 10m in front of the center
        if let positionalEnvironment = environment as? AVAudio3DMixing {
            positionalEnvironment.position = AVAudio3DPoint(x: 0, y: 0, z: 10)
        }
        
        player.scheduleFile(audioFile, at: nil, completionHandler: nil)
        engine.prepare()
        try engine.start()
        player.play()
        
        // Start the timer to update the listener's orientation
         timer = Timer.scheduledTimer(timeInterval: 1.0/60.0, target: self, selector: #selector(updateListenerOrientation), userInfo: nil, repeats: true)
             
        
    } catch let error {
        fatalError("Error: \(error.localizedDescription)")
    }
}

@objc func updateListenerOrientation() {
       // Update yaw
       currentYaw -= rotationSpeed
       if currentYaw < -360 { currentYaw += 360 }
       
       // Set the updated yaw to the listener's orientation
       environment.listenerAngularOrientation = AVAudio3DAngularOrientation(yaw: currentYaw, pitch: 0, roll: 0)
    
    // Print the updated value for debugging
        print("Updated listenerAngularOrientation:", environment.listenerAngularOrientation)
    
   }

deinit {
      timer?.invalidate()
  }

}