❔ UNITY When I manually execute 2 functions it works but not when executing them from 1 function.

public void Initialize()
    {
        DestroyCities();
        GenerateCities();
    }

public void GenerateCities()
    {
        Cities cities = new Cities();
        cities = cities.CreateJSON();

        int i = 0;

        foreach (feature cityData in cities.features)
        {.......

public void DestroyCities()
    {
        for (int
 i = 0; i < transform.childCount; i++) 
        {
            GameObject go = transform.GetChild(i).gameObject;
            StartCoroutine(DestroyFastly(go)); //destroys thing (WORKS)
        }
    }

public void Initialize()
    {
        DestroyCities();
        GenerateCities();
    }

public void GenerateCities()
    {
        Cities cities = new Cities();
        cities = cities.CreateJSON();

        int i = 0;

        foreach (feature cityData in cities.features)
        {.......

public void DestroyCities()
    {
        for (int
 i = 0; i < transform.childCount; i++) 
        {
            GameObject go = transform.GetChild(i).gameObject;
            StartCoroutine(DestroyFastly(go)); //destroys thing (WORKS)
        }
    }

public override void OnInspectorGUI()
    {
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            base.OnInspectorGUI();
            if (check.changed)
            {
                cityGeneration.Initialize();
            }
        }

        if (GUILayout.Button("Initialize Cities"))
        {
            cityGeneration.Initialize();
        }

        if (GUILayout.Button("Generate Cities"))
        {
            cityGeneration.GenerateCities();
        }

        if (GUILayout.Button("Destroy Cities"))
        {
            cityGeneration.DestroyCities();
        }

        DrawSettingsEditor(cityGeneration.shapeSettings, cityGeneration.OnShapeSettingsUpdated, ref cityGeneration.shapeSettingsFoldout, ref shapeEditor);
        DrawSettingsEditor(cityGeneration.citySettings , cityGeneration.OnCitySettingsUpdated , ref cityGeneration.citySettingsFoldout , ref cityEditor);
    }

public override void OnInspectorGUI()
    {
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            base.OnInspectorGUI();
            if (check.changed)
            {
                cityGeneration.Initialize();
            }
        }

        if (GUILayout.Button("Initialize Cities"))
        {
            cityGeneration.Initialize();
        }

        if (GUILayout.Button("Generate Cities"))
        {
            cityGeneration.GenerateCities();
        }

        if (GUILayout.Button("Destroy Cities"))
        {
            cityGeneration.DestroyCities();
        }

        DrawSettingsEditor(cityGeneration.shapeSettings, cityGeneration.OnShapeSettingsUpdated, ref cityGeneration.shapeSettingsFoldout, ref shapeEditor);
        DrawSettingsEditor(cityGeneration.citySettings , cityGeneration.OnCitySettingsUpdated , ref cityGeneration.citySettingsFoldout , ref cityEditor);
    }