ver 3.8 Draw functions issue

Following snippet duplicates drawings when changing symbol or timeframe as shown in the attached image

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;
using cAlgo.Indicators;

namespace cAlgo
{
    [Indicator(IsOverlay = false, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class TestDraw : Indicator
    {
        [Parameter(DefaultValue = 0.0)]
        public double Parameter { get; set; }

        [Output("O", LineColor = "Cyan", PlotType = PlotType.Line, LineStyle = LineStyle.Solid, Thickness = 1)]
        public IndicatorDataSeries O { get; set; }

        [Output("H", LineColor = "Lime", PlotType = PlotType.Line, LineStyle = LineStyle.Solid, Thickness = 1)]
        public IndicatorDataSeries H { get; set; }

        [Output("L", LineColor = "Tomato", PlotType = PlotType.Line, LineStyle = LineStyle.Solid, Thickness = 1)]
        public IndicatorDataSeries L { get; set; }

        [Output("C", LineColor = "White", PlotType = PlotType.Line, LineStyle = LineStyle.Solid, Thickness = 1)]
        public IndicatorDataSeries C { get; set; }


        public List<IndicatorDataSeries> Outs = new List<IndicatorDataSeries>();

        protected override void Initialize()
        {
            Outs.Add(O);
            Outs.Add(H);
            Outs.Add(L);
            Outs.Add(C);
        }

        public override void Calculate(int index)
        {
            O[index] = Bars.OpenPrices.LastValue;
            H[index] = Bars.HighPrices.LastValue;
            L[index] = Bars.LowPrices.LastValue;
            C[index] = Bars.ClosePrices.LastValue;

            string txt = "";
            if (IsLastBar)
            {
                for (int i = 0; i < Outs.Count; i++)
                {
                    DrawIcon(i);
                    txt += Outs[i].LastValue + "\n";
                }
                DrawText(txt);
            }
        }

        public void DrawIcon(int n)
        {
            ChartIconType it;
            Color ic;
            if (Outs[n].IsRising())
            {
                it = ChartIconType.UpArrow;
                ic = Color.Lime;
            }
            else if (Outs[n].IsFalling())
            {
                it = ChartIconType.DownArrow;
                ic = Color.Tomato;
            }
            else
            {
                it = ChartIconType.Circle;
                ic = Color.Yellow;
            }

            IndicatorArea.DrawIcon("icon" + n, it, Bars.Count + 1 + n, Outs[n].LastValue, ic);
        }

        public void DrawText(string txt)
        {
            double mid = (IndicatorArea.TopY + IndicatorArea.BottomY) / 2;
            VerticalAlignment va = Bars.MedianPrices.LastValue > mid ? VerticalAlignment.Bottom : VerticalAlignment.Top;

            IndicatorArea.DrawStaticText("statxt", txt, va, HorizontalAlignment.Right, Color.White);
        }

    }
}