why C++/CLI System::Timers::Timer triggered callback every 20 seconds while set interval to 100ms?

The same codes in C++/CLI act differently as C#. The C# version works fine.

I set a timer which triggered every 100ms, but it actually triggered 20 seconds. I've been puzzled for several days.

C++ codes:

#include "stdafx.h"

using namespace System;
using namespace System::Timers;
using namespace System::Threading;

static void SysTick(Object^ state, ElapsedEventArgs^ e)
{
    DateTime _current = System::DateTime::Now;
    String^ dt_str = String::Format("NOW: @{0}.{1:000}", _current.ToLongTimeString(), _current.Millisecond);
    Console::WriteLine(dt_str);
}

int main(array<System::String ^> ^args)
{
    System::Timers::Timer^ sys_tick = gcnew System::Timers::Timer(100);
    sys_tick->BeginInit();
    sys_tick->AutoReset = true;
    sys_tick->Elapsed += gcnew ElapsedEventHandler(SysTick);
    sys_tick->EndInit();

    sys_tick->Start();
    for (int i = 0; i < 100; i++)
    {
        Console::WriteLine("[{0}] Main thread sleep 1000 ms", i);
        Thread::Sleep(1000);
    }

    return 0;
}

Their output:

[0] Main thread sleep 1000 ms
NOW: @5:59:58 PM.284
[1] Main thread sleep 1000 ms
[2] Main thread sleep 1000 ms
[3] Main thread sleep 1000 ms
[4] Main thread sleep 1000 ms
[5] Main thread sleep 1000 ms
[6] Main thread sleep 1000 ms
[7] Main thread sleep 1000 ms
[8] Main thread sleep 1000 ms
[9] Main thread sleep 1000 ms
[10] Main thread sleep 1000 ms
[11] Main thread sleep 1000 ms
[12] Main thread sleep 1000 ms
[13] Main thread sleep 1000 ms
[14] Main thread sleep 1000 ms
[15] Main thread sleep 1000 ms
[16] Main thread sleep 1000 ms
[17] Main thread sleep 1000 ms
[18] Main thread sleep 1000 ms
[19] Main thread sleep 1000 ms
[20] Main thread sleep 1000 ms
NOW: @6:00:18 PM.421
[21] Main thread sleep 1000 ms
[22] Main thread sleep 1000 ms

Note that the timer triggered every 20s instead of 100ms as specified. Someone on the stackoverflow told me to start the timer in another thread instead of which main() was in. I followed that instruction and the same thing happened again. The problem is not resolved.

Another approach is using Threading::Timer instead of Timer::Timer. I tried, and it also did not resolve the problem.

For reasons I can not use C# in my project. But I still tested these codes in C#. Everything worked fine.

C# codes are:

using System;
using System.Timers;
using System.Threading;

namespace CSharpTimer
{
    class Program
    {
        static void SysTick(object state, ElapsedEventArgs e)
        {
            DateTime now = DateTime.Now;
            Console.WriteLine("NOW: {0}.{1:000}", now.ToLongTimeString(), now.Millisecond);
        }

        static void Main(string[] args)
        {
            System.Timers.Timer timer = new System.Timers.Timer(100);
            timer.BeginInit();
            timer.AutoReset = true;
            timer.Elapsed += new ElapsedEventHandler(SysTick);
            timer.EndInit();

            timer.Start();
            for (int i = 0; i < 100; i++)
            {
                Console.WriteLine("[{0}] Main thread sleep 1000 ms", i);
                Thread.Sleep(1000);
            }
        }
    }
}

And C# outputs are:

[0] Main thread sleep 1000 ms
NOW: 6:01:23 PM.032
NOW: 6:01:23 PM.134
NOW: 6:01:23 PM.242
NOW: 6:01:23 PM.352
NOW: 6:01:23 PM.460
NOW: 6:01:23 PM.575
NOW: 6:01:23 PM.682
NOW: 6:01:23 PM.790
NOW: 6:01:23 PM.899
[1] Main thread sleep 1000 ms
NOW: 6:01:24 PM.007
NOW: 6:01:24 PM.122
NOW: 6:01:24 PM.231
NOW: 6:01:24 PM.339
NOW: 6:01:24 PM.447
NOW: 6:01:24 PM.554
NOW: 6:01:24 PM.663
NOW: 6:01:24 PM.780
NOW: 6:01:24 PM.888
[2] Main thread sleep 1000 ms
NOW: 6:01:24 PM.995
NOW: 6:01:25 PM.104
NOW: 6:01:25 PM.212
NOW: 6:01:25 PM.320