Initialize seems to be called twice on startup

The following code shows that the initialize method seems to be called twice. I verified this in both cAlgo and cTrader. The only impact seems to be performance. If I have an indicator that does some heavy prep work in the initialize method, I'm paying double performance.

Code demonstrating the issue:

using System;
using cAlgo.API;
using cAlgo.API.Indicators;
using System.Runtime.InteropServices;

namespace cAlgo.Indicators
{
    [Indicator(IsOverlay = false)]
    public class NewIndicator : Indicator
    {
        [Parameter(DefaultValue = 0.0)]
        public double Parameter { get; set; }

        [Output("Main")]
        public IndicatorDataSeries Result { get; set; }

        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
        public static extern int MessageBox(IntPtr hWnd, String text, String caption, uint type);

        protected override void Initialize()
        {
            // Initialize and create nested indicators
            log("init Complete");
        }

        public override void Calculate(int index)
        {
            // Calculate value at specified index
            // Result[index] = ...
        }

        public void log(string txt)
        {
            Print(txt);
            MessageBox(new IntPtr(0), txt, "debug", 0);
        }
    }
}