Possible LoadMoreHistory bug

Dear Spotware,

I built a covariance indicator some time ago, it all worked fine but now it looks like it is not working anymore, and i haven't changed the code since i made it, so i was wondering what was going on.

The indicator does not seem to display any output, instead, once put on chart, it goes on loading and loading forever without ever stopping, this is show in the pic below, where the chart cursor has become very small from all the bars loaded:

This is odd, since the indicator calls LoadMoreHistory() in Initialize just once, and not in a continuous, infinite loop.

Here is source code for the indicator:

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;
using cAlgo.Indicators;

namespace cAlgo
{
    [Levels(0, 0.2, -0.2, 1, -1, 0.8, -0.8)]
    [Indicator(IsOverlay = false, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class Covariance : Indicator
    {
        [Parameter("Slow Period", DefaultValue = 120)]
        public int Period { get; set; }
        [Parameter("Fast Period", DefaultValue = 50)]
        public int FastPeriod { get; set; }
        [Parameter()]
        public string FirstSource { get; set; }
        [Parameter()]
        public string SecondSource { get; set; }
        [Parameter()]
        public bool DisplayCorrelation { get; set; }

        [Output("Fast", LineColor = "Cyan")]
        public IndicatorDataSeries Fast { get; set; }
        [Output("Slow", LineColor = "Orange")]
        public IndicatorDataSeries Slow { get; set; }

        private Bars FirstSeries, SecondSeries;

        protected override void Initialize()
        {
            FirstSource = FirstSource == "" ? Symbol.Name : FirstSource;
            SecondSource = SecondSource == "" ? Symbol.Name : SecondSource;

            FirstSeries = MarketData.GetBars(TimeFrame, FirstSource);
            SecondSeries = MarketData.GetBars(TimeFrame, SecondSource);
            FirstSeries.LoadMoreHistory();
            SecondSeries.LoadMoreHistory();

            IndicatorArea.DrawHorizontalLine("0.8", 0.8, Color.Green);
            IndicatorArea.DrawHorizontalLine("-0.8", -0.8, Color.DarkRed);
        }

        public override void Calculate(int index)
        {
            Fast[index] = ResultAt(index, FastPeriod);
            Slow[index] = ResultAt(index, Period);
        }

        public double ResultAt(int index, int period)
        {
            int index1 = FirstSeries.OpenTimes.GetIndexByTime(Bars.OpenTimes[index]);
            int index2 = SecondSeries.OpenTimes.GetIndexByTime(Bars.OpenTimes[index]);

            double result;
            ///Expected values for X and Y
            double firstMean = 0, secondMean = 0;

            for (int i = 0; i < period; ++i)
            {
                firstMean += FirstSeries.ClosePrices[index1 - i];
                secondMean += SecondSeries.ClosePrices[index2 - i];
            }

            firstMean /= period;
            secondMean /= period;

            ///Expected value for (X - E[X])(Y - E[Y])
            double productMean = 0;

            for (int i = 0; i < period; ++i)
            {
                productMean += (FirstSeries.ClosePrices[index1 - i] - firstMean) * (SecondSeries.ClosePrices[index2 - i] - secondMean);
            }

            productMean /= period;

            ///Display covariance
            result = productMean;

            if (DisplayCorrelation)
            {
                double firstStd = 0, secondStd = 0;

                for (int i = 0; i < period; ++i)
                {
                    firstStd += Math.Pow(FirstSeries.ClosePrices[index1 - i] - firstMean, 2);
                    secondStd += Math.Pow(SecondSeries.ClosePrices[index2 - i] - secondMean, 2);
                }

                firstStd = Math.Sqrt(firstStd * 1 / (period));
                secondStd = Math.Sqrt(secondStd * 1 / (period));

                result = productMean / (firstStd * secondStd);
            }
            return result;
        }
    }
}