Laravel cards shuffling code does not returns 52 cards

Question

this is my code;

following functions are used to generate a new deck, length of the deck where it will be split and random number of shuffles to be performed.

  public function newDeck()
  {
      $suits = ['S', 'H', 'C', 'D'];
      $values = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13];

      foreach($suits as $suit)
      {
          foreach($values as $value)
          {
              $deck[$suit . $value] = $value;
          }
      }

      return $deck;
  }
  //this function gives the length where the deck will be sliced
  public function cutLength($len)
  {
      for ($i = 0; $i < 1; ++$i) {
          $cutLength[] = rand(1,$len-1);
      }

      return $cutLength;
  }

  //this function gives the number of total shuffles
  public function shuffleCount($count)
  {
      for ($i = 0; $i < 1; ++$i) {
          $shuffleCount[] = rand(1,$count);
      }

      return $shuffleCount;
  }

and the following code shuffles the card deck. Here I am just retrieving the card deck from a db.

$left = json_decode(Game::where('gamer_id',
    $request->id)->latest()->first()->game_deck, TRUE);

//set of single shuffles
$m = $game->shuffleCount(5);
for($j = 0; $j < $m[0]; $j++) {

    //count of complete deck
    $leftLength = count($left);

    //place from where the deck will be seperated
    $fullDeckCutLength = $game->cutLength($leftLength);

    //right is the lower portion of cards
    $right = array_slice($left, $fullDeckCutLength[0], $leftLength - $fullDeckCutLength[0]);

    //left is the upper portion of cards
    $left = array_slice($left, 0, $fullDeckCutLength[0]);

    //empty the full deck cut length array
    $fullDeckCutLength = [];

    //check the thickness of the cards in the right hand
    $rightLength = count($right);

    //if less than 10 cards in right hand, then this if will just place them on top of the cards in right hand
    if($rightLength < 0.2 * $leftLength) {
        $left = array_merge($right, $left);
        $right = [];
        continue;
    } else {
        //Single shuffle
        $n = $game->shuffleCount(10);

        for($i = 0; $i < $n[0]; $i++) {
            //count cards in right hand
            $rightLength = count($right);
            //determine how many cards will be slid from the top of right deck to the top of left deck
            $rightDeckCutLength = $game->cutLength($rightLength);
            //remove the cards from the top of right hand deck
            $rtl = array_slice($right, 0, $rightDeckCutLength[0]);

            //place the cards from the top of right deck to the top of left deck
            $left = array_merge($rtl, $left);

            //empty the right to left array
            $rtl = [];

            //remaining cards in the right hand deck
            $right = array_slice($right, $rightDeckCutLength[0], $rightLength - $rightDeckCutLength[0]);

            //empty the right deck cut length array
            $rightDeckCutLength = [];

            //check the thickness of the cards in the right hand
            $rightLength = count($right);
            //if the cards in RH are less than 10 then continue the loop
            if($rightLength < 0.2 * $leftLength) {
                $left = array_merge($right, $left);
                $right = [];
                $n = [];
                break;
            } elseif($i == $n[0]) {
                $left = array_merge($right, $left);
                $right = [];
                $n = [];
            }
        }
    }
}

dd($left);

Now this code is shuffling the cards as per intended but the issue I am getting is that the output I am getting doesnot always has 52 cards, most of the times it is 52 cards but sometimes the output is less than 52. Can someone point out the issue, please.