Sound gone when scaled video

[ahmedsafadii]

When i try to scale video speed it up or slow it the voice is gone but the videos works

let resource = AVAssetTrackResource(asset: asset)
                    resource.scaledDuration = CMTime(seconds: 5.0, preferredTimeScale: 600)
                    resource.duration = CMTime(seconds: 5.0, preferredTimeScale: 600)
                    let trackItem = TrackItem(resource: resource)
                    trackItem.videoConfiguration.contentMode = .aspectFill

[ahmedsafadii]

@vitoziv