Cluster, MKMapView show many time same annotation - swift

Question

So, I have a swift application (swift 3) who use a map, in this map I have many annotation who gets up to date when user change region of map.
I wanted to use the pod "Cluster", I add it and when I zoom in to show what was in the cluster, the annotations appear several times almost at the same place (some time it form a circle, see picture)
I have already tried to filter my list to get only once instance of annotation in cluster but it doesn't works.
This method is call each time the user change region :
func createAnnotations(pois list:[PlaceModel]) {
poiAnnotations.removeAll()
let filteredAnnotations = mapView.annotations.filter { annotation in
//if annotation is MKUserLocation { return false } // don't remove MKUserLocation
if let temp = annotation.subtitle, let value = temp {
return value == "Place"
}
return false
}
clusterManager.remove(poiAnnotations)
clusterManager.remove(filteredAnnotations)
for poi in list {
let centerLocation = CLLocation(latitude: mapView.centerCoordinate.latitude, longitude: mapView.centerCoordinate.longitude)
if poi.getLocation().distance(from: centerLocation) > Double(Constants.POI_Radius) {
continue
}
let annotation = Annotation()
annotation.coordinate = CLLocationCoordinate2D(latitude: poi.latitude!, longitude: poi.longitude!)
annotation.title = poi.name!
annotation.subtitle = "Place"
annotation.type = .image( Images.MapPins.velhop)
// For first value
if poiAnnotations.isEmpty {
poiAnnotations.append(annotation)
}
for pois in poiAnnotations {
if poiAnnotations.contains(where: {$0.title == poi.name}) {
// Do nothing
} else {
poiAnnotations.append(annotation)
}
}
}
clusterManager.add(poiAnnotations)
}
And Here the place where the clusters and the annotations are created :
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
if let annotation = annotation as? ClusterAnnotation {
let identifier = "Cluster"
var view = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)
// Type for cluster
let color = UIColor(red: 255/255, green: 149/255, blue: 0/255, alpha: 1)
let type:ClusterAnnotationType = .color(color, radius: 25)
if let view = view as? BorderedClusterAnnotationView {
view.annotation = annotation
view.configure(with: type)
} else {
view = BorderedClusterAnnotationView(annotation: annotation, reuseIdentifier: identifier, type: type, borderColor: .white)
}
return view
} else {
let identifier = "Pin"
var view = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as? MKPinAnnotationView
if let view = view {
view.annotation = annotation
} else {
view = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
}
return view
}
}
I tried several things that did not succeed..
Thanks in advance.