hidden series created by createdataseries not work, but mark as output work!

Hi, I follow this API to create a hidden series

without success.

here my code:

// -------------------------------  Indicator Code ----------------------------------------
// Don't mark this data series as [Output]
public IndicatorDataSeries BreakState { get; set; }

protected override void Initialize()
{
  BreakState = CreateDataSeries();
}

public override void Calculate(int index)
{
  BreakState[index] = 1; // Fixed value = 1 for testing
}

public int getLastBreakState()
    {
      var a = BreakState.LastValue; // ====> a is always NaN
      return a;
    }

// -------------------------------- Inside cBot file: ---------------------------------
private MyAboveIndicator myAboveIndicator;

// cBot onStart()
myAboveIndicator= Indicators.GetIndicator<MyAboveIndicator>(
   // with Some of my params here
);

// cBot onTick()
int indicatorState = myAboveIndicator.getLastBreakState(); // ===> It's always NaN, expected: Must be 1

I must mark my data series as Output, then it work normally.

Without marking as output, it always NaN.

Is this a bug of cAlgo API ??