Debug my iCustom EA

I have a custom indicator, and want to create an EA than using "iCUSTOM" and "PRINT", make the EA can read and print the indicator values at journel for each bar correctly when I put this EA into backtesting, i tried to make it, but it can't get the right values, so would like someone help me to fix it

Pls read through my indicator and EA, and make sure you know what’w wrong with my EA before you accpet this job, thanks

My indicator

//+------------------------------------------------------------------+
//|     MA_Direction_SingleBuffer_MQL4.mq4                          |
//|      |
//|   適用於 MQL4，便於 EA 調用 buffer[0]，與圖表分色並存           |
//+------------------------------------------------------------------+
#property indicator_separate_window
#property indicator_buffers 3
#property indicator_color1 Lime    // Up
#property indicator_color2 Red     // Down
#property indicator_color3 Gray    // Flat
#property strict

input int MAPeriod = 14;

// Buffers for plotting (only one active per bar)
double bufferUp[];    // buffer 0 - EA 調用此值
double bufferDown[];  // buffer 1 - 僅視覺繪圖用
double bufferFlat[];  // buffer 2 - 僅視覺繪圖用

//+------------------------------------------------------------------+
int OnInit()
  {
   IndicatorShortName("MA_Direction_SingleBuffer");

   SetIndexBuffer(0, bufferUp);
   SetIndexStyle(0, DRAW_HISTOGRAM, STYLE_SOLID, 2);
   SetIndexLabel(0, "Slope");

   SetIndexBuffer(1, bufferDown);
   SetIndexStyle(1, DRAW_HISTOGRAM, STYLE_SOLID, 2);
   SetIndexLabel(1, "Down");

   SetIndexBuffer(2, bufferFlat);
   SetIndexStyle(2, DRAW_HISTOGRAM, STYLE_SOLID, 1);
   SetIndexLabel(2, "Flat");

   return INIT_SUCCEEDED;
  }
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime& time[],
                const double& open[],
                const double& high[],
                const double& low[],
                const double& close[],
                const long& tick_volume[],
                const long& volume[],
                const int& spread[])
  {
   if (rates_total < MAPeriod + 2)
      return 0;

   int start = MathMax(prev_calculated - 1, 1);

   for (int i = start; i < rates_total - 1; i++)
     {
      double ma_now = iMA(NULL, 0, MAPeriod, 0, MODE_SMA, PRICE_CLOSE, i);
      double ma_prev = iMA(NULL, 0, MAPeriod, 0, MODE_SMA, PRICE_CLOSE, i + 1);
      double slope = ma_now - ma_prev;

      // 寫入主輸出 buffer（供 EA 調用）
      bufferUp[i] = slope;

      // 視覺分色（其他兩 buffer 只為圖表用）
      if (slope > 0)
        {
         bufferDown[i] = 0;
         bufferFlat[i] = 0;
        }
      else if (slope < 0)
        {
         bufferDown[i] = slope;
         bufferFlat[i] = 0;
         bufferUp[i] = 0;
        }
      else
        {
         bufferDown[i] = 0;
         bufferFlat[i] = 0.0000001;  // 微量顯示灰色線
         bufferUp[i] = 0;
        }
     }

   return rates_total;
  }

My EA

//+------------------------------------------------------------------+
//|                             MA_Direction_SingleBuffer_Reader.mq4 |
//|                                  Copyright 2024, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+

#property strict

input int MAPeriod = 14;   
input double Threshold = 0.00001; 

double MA_Value;
datetime OpenTime = iTime(Symbol(), PERIOD_CURRENT, 0);

//+------------------------------------------------------------------+
int OnInit()
  {
   Print("MA Reader EA initialized.");
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
void OnTick()
  {
   if (newC())
     {
      MA_Value = iCustom(Symbol(), PERIOD_CURRENT, "MA_Direction_SingleBuffer", MAPeriod, 0, 1);

      if (MA_Value > Threshold)
         Print("📈 UP: ", DoubleToString(MA_Value, 6));
      else if (MA_Value < -Threshold)
         Print("📉 DOWN: ", DoubleToString(MA_Value, 6));
      else
         Print("➖ FLAT: ", DoubleToString(MA_Value, 6));
     }
  }
//+------------------------------------------------------------------+
bool newC()
  {
   datetime newOpenTime = iTime(Symbol(), PERIOD_CURRENT, 0);
   if (newOpenTime != OpenTime)
     {
      OpenTime = newOpenTime;
      return true;
     }
   return false;
  }
//+------------------------------------------------------------------+

Pls help