How to Set Gmap.Net Controler on Main form fit

Question

I'm using Gmap.net library to display map on a form by C# .Net, it works great but the map controller is smaller than main windows form when zoom is '1' while I set Dock property controller to Fill.

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

            // config map         
            gMapControl1.MapProvider = GMapProviders.GoogleSatelliteMap;
            gMapControl1.Position = new PointLatLng(54.6961334816182, 25.2985095977783);
            gMapControl1.MinZoom = 0;
            gMapControl1.MaxZoom = 24;
            gMapControl1.Zoom = 1;

            gMapControl1.Dock = DockStyle.Fill;

        }


    }

image of problem

I expect that the controller display on the main form as Fit.