Unable to encode/decode packet (nemisys)

I'm trying to implement SynapseAPI for PocketMine-MP, but whenever I encode and decode ConnectPacket the data aren't correct

PHP:

<?php

namespace SynapseAPI\network\protocol;

class ConnectPacket extends DataPacket {
   const NETWORK_ID = Info::CONNECT_PACKET;

   public $protocol = Info::CURRENT_PROTOCOL;
   public $maxPlayers;
   public $isMainServer;
   public $isLobbyServer = true;
   public $transferShutdown = true;
   public $description;
   public $password;

   public function encode() {
      $this->reset();
      $this->putInt($this->protocol);
      $this->putInt($this->maxPlayers);
      $this->putBool($this->isMainServer);
      $this->putBool($this->isLobbyServer);
      $this->putBool($this->transferShutdown);
      $this->putString($this->description);
      $this->putString($this->password);
   }

   public function decode() {
      $this->protocol = $this->getInt();
      $this->maxPlayers = $this->getInt();
      $this->isMainServer = $this->getBool();
      $this->isLobbyServer = $this->getBool();
      $this->transferShutdown = $this->getBool();
      $this->description = $this->getString();
      $this->password = $this->getString();
   }
}


PHP:

/**
* @return string
*/
public function getString() : string{
    return $this->get($this->getUnsignedVarInt());
}

/**
* @param string $v
*/
public function putString(string $v) : void{
    $this->putUnsignedVarInt(strlen($v));
    $this->put($v);
}


Other functions like getBool(), putInt() etc are from BinaryStream

Now I encode & decode the packet

PHP:

$pk = new ConnectPacket();
$pk->password = "test123456789";
$pk->isMainServer = true;
$pk->isLobbyServer = true;
$pk->description = "test";
$pk->maxPlayers = 20;
$pk->protocol = 10;
$pk->encode();
$pk->decode();


Result:

Code:

object(SynapseAPI\network\protocol\ConnectPacket)#181 (9) {
  ["protocol"]=>
  int(33554432)
  ["maxPlayers"]=>
  int(167772160)
  ["isMainServer"]=>
  bool(true)
  ["isLobbyServer"]=>
  bool(true)
  ["transferShutdown"]=>
  bool(true)
  ["description"]=>
  string(1) ""
  ["password"]=>
test123456789"est
  ["offset"]=>
  int(130)
  ["buffer"]=>
  string(31) "
test123456789"
}

not sure what is causing this