Code working only on forex not on CFD

[Merlin Jules Baptiste Girard- Razel]

//+------------------------------------------------------------------+
//|                                                   Investtest.mq5 |
//|                                  Copyright 2024, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2024, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
#include<Trade\Trade.mqh>
CTrade trade;
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+

static int ordersPlacedToday = 0;
int maxOrdersPerDay = 1;

void OnTick()
  {
  
static datetime Old_Time;
datetime New_Time[1];
bool IsNewBar = false;

int copied = CopyTime(_Symbol, PERIOD_D1, 0, 1, New_Time);
if(copied>0)
   {
      if(Old_Time != New_Time[0])
      {
         IsNewBar = true;
         Old_Time = New_Time[0];
         ordersPlacedToday = 0;
      }
   }




double ask = NormalizeDouble(SymbolInfoDouble(_Symbol,SYMBOL_ASK),_Digits);

double Max5j = iHighest(_Symbol, PERIOD_H1, MODE_HIGH, 120, 0);

double Max3j = iHighest(_Symbol, PERIOD_H1, MODE_HIGH, 72, 0);

double Max1j = iHighest(_Symbol, PERIOD_H1, MODE_HIGH, 24, 0);

double Max4h = iHighest(_Symbol, PERIOD_H1, MODE_HIGH, 4, 0);


if (ask<=((Max4h)*0.99) && ordersPlacedToday < maxOrdersPerDay)
   {
   trade.Buy( 1, NULL, 0.0, 0,ask*1.05, "order succeded");
   ordersPlacedToday++;
   }
else if (ask<=((Max1j)*0.99) && ordersPlacedToday < maxOrdersPerDay)
   {
   trade.Buy( 1, NULL, 0.0, 0,ask*1.05, "order succeded");
   ordersPlacedToday++;
   }
else if (ask<=((Max3j)*0.99) && ordersPlacedToday < maxOrdersPerDay)
   {
   trade.Buy( 1, NULL, 0.0, 0,ask*1.05, "order succeded");
   ordersPlacedToday++;
   }
else if (ask<=((Max5j)*0.99) && ordersPlacedToday < maxOrdersPerDay)
   {
   trade.Buy( 1, NULL, 0.0, 0,ask*1.05, "order succeded");
   ordersPlacedToday++;
   } 
  }

Here is my code, it does work on forex but when i try to make it work on Shares CFD, it works for a few month and then stops buying without explanation even if margin is available.

Any help or explanation?

Thanks