[Custom Inspector] Selecting Gizmo in Scene View and issues

Hi,

I am creating my own waypoint system for AI and decided to implement custom inspector for handling waypoints. I didn't want to use gameobjects as there would be too much work for other users. That's why I decided to draw gizmos and select them in scene view. I found a solution how to do it, however, it doesn't seem to work as I wanted and just selects the first gizmo I drew, even when I click other gizmos.

Here is some code with my implementation:

 public class AIWaypointsInspector : Editor {
 
 //_aiWaypoints.positions is a vector3[] with waypoints positions; IMPORTANT NOTE: I previously added two waypoints there to check the script
 //_aiWaypoints.selected is a bool[] which shows which waypoint is selected
 public override void OnInspectorGUI() {
         if (this._aiWaypoints == null) {
             this._aiWaypoints = (AIWaypoints)target;
         }
             this.DrawWaypoints();
     }
 
     private void DrawWaypoints() {
             Vector3 vec;
             this._moreThanOneSelected = false;
             for (int i = 0; i < this._aiWaypoints.positions.Length; i++) {
                 EditorGUI.BeginChangeCheck();
                 bool sel = EditorGUILayout.ToggleLeft("", this._aiWaypoints.selected[i]);
                 if (EditorGUI.EndChangeCheck()) {
                     if (sel != this._aiWaypoints.selected[i]) {
                         this._aiWaypoints.selected[i] = sel;
                         SceneView.RepaintAll();
                     }
                 }
                 EditorGUI.BeginChangeCheck();
                 vec = EditorGUILayout.Vector3Field("", this._aiWaypoints.positions[i]);
                 if (EditorGUI.EndChangeCheck()) {
                     if (vec != this._aiWaypoints.positions[i]) {
                         this._aiWaypoints.positions[i] = vec;
                         SceneView.RepaintAll();
                     }
                 }
             }
     
     }
 
     private void OnSceneGUI() {
         if (this._aiWaypoints == null) {
             this._aiWaypoints = (AIWaypoints)target;
         }
         Vector3 vec;
         
         if (Event.current.type == EventType.MouseDown) {
             if (Event.current.button == 0) {
                 Ray ray = HandleUtility.GUIPointToWorldRay(Event.current.mousePosition);
                 SphereCollider sph = this._aiWaypoints.gameObject.AddComponent<SphereCollider>();
                 sph.radius = 1f;
                 for (int i = 0; i < this._aiWaypoints.positions.Length; i++) {
                     sph.center = this._aiWaypoints.positions[i];
                     if (Physics.Raycast(ray)) {
                         this._aiWaypoints.selected[i] = true;
                         break;
                     }
                 }
                 DestroyImmediate(this._aiWaypoints.gameObject.GetComponent<SphereCollider>());
             }
         }
         for (int i = 0; i < this._aiWaypoints.positions.Length; i++) {
             if (this._aiWaypoints.selected[i]) {
                 EditorGUI.BeginChangeCheck();
                 vec = Handles.PositionHandle(this._aiWaypoints.positions[i], Quaternion.identity);
                 if (EditorGUI.EndChangeCheck()) {
                     if (vec != this._aiWaypoints.positions[i]) {
                         this._aiWaypoints.positions[i] = vec;
                     }
                 }
             }
         }
 
         if (GUI.changed) {
             EditorUtility.SetDirty(this._aiWaypoints);
         }
     }}

I don't know what I do wrong. I will be grateful for any suggestions and help.