MQL4 - EA - Placing an order based on iCustom indicator - Order placement did not follow the signal correctly?

Hi all,

I'm trying to do these simple things, but I don't know why it didn't work:

1. Get a signal from iCustom indicator (Super-Arrow) for the 2 previous candle (shift 2 candles back),
2. When a buy signal emerges, then place a BUY order, and also draw a vertical line so that I can see if the open position matches the position of the signal.

Here's the code for the EA:

//+------------------------------------------------------------------+
//|                                                      ProjectName |
//|                                      Copyright 2018, CompanyName |
//|                                       http://www.companyname.net |
//+------------------------------------------------------------------+
#property copyright "Copyright 2020, MT4"
#property link      "https://www.metatrader.com"
#property version   "1.00"
#property strict

input double Lots = 0.1;//Volume to trade
input int TakeProfitPoints = 50;//Take profit in points
input int StopLossPoints = 80;//Stop loss in points
input int SlippagePoints = 3;//Maximum slippage in points
input int PreviousCandle = 2;//Look back to X number of candles

//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
   int op_result = 0;
   double buy = 0, sell = 0, tp_price = 0, sl_price = 0;
   buy = iCustom(_Symbol, 0, "super-arrow-indicator", 0, PreviousCandle);
   sell = iCustom(_Symbol, 0, "super-arrow-indicator", 1, PreviousCandle);

   if(OrdersTotal() == 0)
      if(buy != EMPTY_VALUE && buy > 0)
        {
         tp_price = Ask + NormalizeDouble(TakeProfitPoints * _Point, _Digits);
         sl_price = Ask - NormalizeDouble(StopLossPoints * _Point, _Digits);
         op_result = OrderSend(_Symbol, OP_BUY, Lots, Ask, SlippagePoints, sl_price, tp_price, NULL, 0, 0, clrGreen);
         CreateVerticalLine("BUY", clrYellow);
        }
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void CreateVerticalLine(string lineName, color lineColour)
  {
   ObjectCreate(0,StringConcatenate("VLine_", lineName, "_", (string)TimeCurrent()),OBJ_VLINE,0,TimeCurrent(),0);
   ObjectSetInteger(0,StringConcatenate("VLine_", lineName, "_", (string)TimeCurrent()),OBJPROP_COLOR, lineColour);
  }
//+------------------------------------------------------------------+

And I have also attached both the EA source file and the indicator EX4 file.

Please if you could help or at least point out what was my mistake, that'd be greatly appreciated.

Thank you,

insignificant.