第一行匹配，但其他行不匹配password_verify

这是我用盐将哈希密码放在数据库上的注册码。

              <?php
          include '../database/connectDB.php';
            if (isset($_POST['submit']))
{       
                $username= $_POST['leguser'] ;
                $password= $_POST['legpass'] ;  
                $options = [
                    'cost' => 11,
                    'salt' => mcrypt_create_iv(22, MCRYPT_DEV_URANDOM),
                ];
                $pwhash = password_hash($password, PASSWORD_DEFAULT, $options)."'n";
                $username = mysql_real_escape_string($username);
                $password = mysql_real_escape_string($password);
    $query = mysql_query("SELECT * FROM tbl_users WHERE fld_username = '". $username ."'"); 
                    if (mysql_num_rows($query) > 0) 
                    { 
                         echo "<script>alert('Username already used!');</script>"; }
                    else
                    {                           
     mysql_query("INSERT INTO `tbl_users`(fld_username,fld_password) 
     VALUES ('$username','$pwhash')"); 
                    }                          
}
            ?> 

这是我验证密码的登录代码

    <?php 
$DB_HOST = 'localhost';
$DB_USER = 'root';
$DB_PASS = '';
$DB_NAME = 'rsi_db';
$conn = new mysqli($DB_HOST, $DB_USER, $DB_PASS, $DB_NAME);
if($conn->connect_errno > 0) {
  die('Connection failed [' . $conn->connect_error . ']');
}

if (isset($_POST['submit']))
    {       
                    $username= $_POST['user'] ;
                    $password= $_POST['pass'] ; 
        $sql = "SELECT * FROM tbl_users WHERE fld_username = '$username'";
        $result = $conn->query($sql);
        if ($result->num_rows === 1) {
        $row = $result->fetch_array(MYSQLI_ASSOC);
        if (password_verify($password, $row['fld_password'])) {
        echo "Match";
        }
        else 
        {
        echo "not match";
        }                 
    }
    }
    ?>

起初我注册了用户名= 1和密码= 1并尝试登录，这是匹配的，但是当我尝试注册有效的用户和密码时，它不匹配。 有人可以帮助我进一步解决此问题吗？

提前谢谢你，我只是一个 php 初学者，请不要很难:)