My indicator "iCUSTOM" template

i have an indicator called "MA_Direction_SingleBuffer", and then create another indicator called "TrendStrength_BuyOnly" to calcualate the values of  "MA_Direction_SingleBuffer", until here, it seems work well  ( i am not sure, but at least both are work well when i put them in chart), now i want to create a EA, that can read the value of "TrendStrength_BuyOnly" for every bar, but doesn't work, so i wonld like someone help me to fix them, and tell me what's wrong with my code, pls make sure you can fix it before take this job

Here are the indicators and EA

MA_Direction_SingleBuffe

//+------------------------------------------------------------------+
//|     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;
  }

TrendStrength_BuyOnly

//+------------------------------------------------------------------+
//|     TrendStrength_BuyOnly.mq4                                    |
//|     計算近 LookbackBars 根 MA 斜率的趨勢強度（做多為主）         |
//|     資料來源：MA_Direction_SingleBuffer 的 buffer[0]            |
//+------------------------------------------------------------------+
#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 DodgerBlue
#property indicator_width1 2
#property indicator_label1 "TrendStrength_BuyOnly"
#property strict

// --- 輸入參數
input int MAPeriod = 14;                 // 傳給 MA_Direction_SingleBuffer 用
input int LookbackBars = 90;            // 回顧 K 線數量
input double SlopeThreshold = 0.05;     // 視為有效斜率的門檻

// --- 指標 buffer
double TrendStrengthBuffer[];

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

   SetIndexBuffer(0, TrendStrengthBuffer);
   SetIndexStyle(0, DRAW_LINE);
   SetIndexLabel(0, "Buy Trend Strength");

   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 < LookbackBars + 1)
      return 0;

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

   for (int i = start; i < rates_total - 1; i++)
     {
      double score = 0;

      for (int j = 0; j < LookbackBars; j++)
        {
         double slope = iCustom(NULL, 0, "MA_Direction_SingleBuffer", MAPeriod, 0, i + j);

         if (slope > SlopeThreshold)
            score += slope;
         else if (slope < -SlopeThreshold)
            score -= MathAbs(slope) * 0.5;
         else
            score -= 0.1; // 側向或雜訊
        }

      TrendStrengthBuffer[i] = score;
     }

   return rates_total;
  }
//+------------------------------------------------------------------+

EA

//+------------------------------------------------------------------+
//|                                      TrendStrengthReader_EA.mq4  |
//|                       Copyright 2025, The Blue Teams Academy     |
//|                  https://www.TheBlueTeamsAcademy.com             |
//+------------------------------------------------------------------+
#property strict
#property copyright "Copyright 2025, The Blue Teams Academy"
#property link      "https://www.TheBlueTeamsAcademy.com"
#property version   "1.00"

//--- 變數宣告
double TrendStrengthValue;
datetime OpenTime = 0;

//+------------------------------------------------------------------+
//| Expert 初始化                                                    |
//+------------------------------------------------------------------+
int OnInit()
  {
   Print("✅ TrendStrengthReader_EA initialized.");
   OpenTime = iTime(Symbol(), PERIOD_CURRENT, 0);
   return INIT_SUCCEEDED;
  }

//+------------------------------------------------------------------+
//| OnTick                                                            |
//+------------------------------------------------------------------+
void OnTick()
  {
   if (IsNewBar())
     {
      TrendStrengthValue = iCustom(Symbol(), PERIOD_CURRENT, "TrendStrength_BuyOnlyv2", 0, 1);

      if (TrendStrengthValue == EMPTY_VALUE)
         Print("❌ EMPTY_VALUE at bar 1 (未有資料填入)");
      else if (TrendStrengthValue == 0.0)
         Print("⚠️ Zero value at bar 1 (可能資料不足或斜率弱)");
      else
         Print("✅ TrendStrength (Bar 1): ", DoubleToString(TrendStrengthValue, 5));
     }
  }

//+------------------------------------------------------------------+
//| 判斷是否為新K線                                                  |
//+------------------------------------------------------------------+
bool IsNewBar()
  {
   datetime newTime = iTime(Symbol(), PERIOD_CURRENT, 0);
   if (newTime != OpenTime)
     {
      OpenTime = newTime;
      return true;
     }
   return false;
  }
//+------------------------------------------------------------------+