"Max number of bars" Auto-Detect does not work correctly in some cases (Multicharts .NET)

using System;
using System.Drawing;
using PowerLanguage.Function;

namespace PowerLanguage.Indicator
{

[SameAsSymbol(true)]
public class bugtest : IndicatorObject
{
public bugtest(object _ctx):base(_ctx) {}

private IPlotObject plot1;



public bool myPattern(IInstrument _bars, IOutput _out)
{

    _out.WriteLine("myPattern() at bar: {0} \t CloseValue: {1}" , _bars.FullSymbolData.Current, _bars.CloseValue); 


    if(_bars.Close[0] > _bars.High[1])           // <-------------
    {
        return true;
    }
    else
    {
        return false;   
    }
}   



protected override void Create() 
{
    plot1 = AddPlot(new PlotAttributes("", EPlotShapes.Point, Color.Yellow) );    
}



protected override void StartCalc() 
{
    //Output.Clear();
    Output.WriteLine("Hello from StartCalc-Function");
}



protected override void CalcBar()
{
    if( myPattern(this.Bars, this.Output) == true)
    {
        plot1.Set(Bars.High[0],  Color.Yellow); 
    }
}

}

}