It doesn't work correctly before making the button

Good time of day. I made my own button, where I did everything necessary for its further operation. Next, I encountered the smoothness of this button, it does not suit me from the word at all, and I decided to use DoubleBuffered, after adding DoubleBuffered, I encountered another problem, more details you can see on the screenshot. In the background in the app, I use an image. I ask for help because I can't solve this problem.

using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace Test_Project
{
    public class Test_Button : Control
    {
        public Color BackColor2 { get; set; }
        public Color ButtonBorderColor { get; set; }
        //----------
        public Color ButtonHighlightColor { get; set; }
        //-----
        public Color ButtonHighlightColor2 { get; set; }
        //-----
        public Color ButtonHighlightForeColor { get; set; }
        //------
        public Color ButtonPressedColor { get; set; }
        //------
        public Color ButtonPressedColor2 { get; set; }
        //------
        public Color ButtonPressedForeColor { get; set; }

        //--------
        public int ButtonRoundRadius { get; set; }
        //--------

        private bool IsHighlighted;
        private bool IsPressed;

        public Test_Button()
        {
            Size = new Size(100, 40);
            ButtonRoundRadius = 30;
            BackColor = Color.Gainsboro;
            BackColor2 = Color.Silver;
            ButtonBorderColor = Color.Black;
            ButtonHighlightColor = Color.Orange;
            ButtonHighlightColor2 = Color.OrangeRed;
            ButtonHighlightForeColor = Color.Black;

            ButtonPressedColor = Color.Red;
            ButtonPressedColor2 = Color.Maroon;
            ButtonPressedForeColor = Color.White;
            //=============
            SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.SupportsTransparentBackColor | ControlStyles.UserPaint, true);
            DoubleBuffered = true;
        }
        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams createParams = base.CreateParams;
                createParams.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT
                return createParams;
            }
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            Graphics graph = e.Graphics;
            graph.SmoothingMode = SmoothingMode.HighQuality;
            graph.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graph.Clear(Parent.BackColor);

            var foreColor = IsPressed ? ButtonPressedForeColor : IsHighlighted ? ButtonHighlightForeColor : ForeColor;
            var backColor = IsPressed ? ButtonPressedColor : IsHighlighted ? ButtonHighlightColor : BackColor;
            var backColor2 = IsPressed ? ButtonPressedColor2 : IsHighlighted ? ButtonHighlightColor2 : BackColor2;


            using (var pen = new Pen(ButtonBorderColor, 1))
                e.Graphics.DrawPath(pen, Path);

            using (var brush = new LinearGradientBrush(ClientRectangle, backColor, backColor2, LinearGradientMode.Vertical))
                e.Graphics.FillPath(brush, Path);


            using (var brush = new SolidBrush(foreColor))
            {
                var sf = new StringFormat { Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center };
                var rect = ClientRectangle;
                rect.Inflate(-4, -4);
                e.Graphics.DrawString(Text, Font, brush, rect, sf);
            }

        }

        protected override void OnMouseEnter(EventArgs e)
        {
            base.OnMouseEnter(e);
            IsHighlighted = true;
            Parent.Invalidate(Bounds, false);
            Invalidate();
        }


        protected override void OnMouseLeave(EventArgs e)
        {
            base.OnMouseLeave(e);
            IsHighlighted = false;
            IsPressed = false;
            Parent.Invalidate(Bounds, false);
            Invalidate();
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            IsPressed = true;
            Parent.Invalidate(Bounds, false);
            Invalidate();
        }

        protected override void OnMouseUp(MouseEventArgs e)
        {
            base.OnMouseUp(e);
            Parent.Invalidate(Bounds, false);
            Invalidate();
            IsPressed = false;
        }

        protected GraphicsPath Path
        {
            get
            {
                var rect = ClientRectangle;
                rect.Inflate(-1, -1);
                return GetRoundedRectangle(rect, ButtonRoundRadius);
            }
        }

        public static GraphicsPath GetRoundedRectangle(Rectangle rect, int d)
        {
            var gp = new GraphicsPath();

            gp.AddArc(rect.X, rect.Y, d, d, 180, 90);
            gp.AddArc(rect.X + rect.Width - d, rect.Y, d, d, 270, 90);
            gp.AddArc(rect.X + rect.Width - d, rect.Y + rect.Height - d, d, d, 0, 90);
            gp.AddArc(rect.X, rect.Y + rect.Height - d, d, d, 90, 90);
            gp.CloseFigure();

            return gp;
        }
    }
}

Add the one line below to your Test_Button constructor to make your button rounded instead of rectangular:

public Test_Button()
{
    // ... other code in your constructor ...

    this.Region = new Region(GetRoundedRectangle(ClientRectangle, ButtonRoundRadius));
}