通过VPN插入SQL会产生奇怪的结果

Question

我不确定我做错了什么？每当我连接到办公室wifi并测试我的应用程序注册功能时，电子邮件部分会显示与我的输入不同的结果。例如，如果我输入test@test.com并进入phpmyadmin进行检查，则为test@nefiewx.legsq.nl3.gsr.awhoer.net。我的代码有问题还是我必须避免使用wifi？

我不得不使用vpn访问我的phpmyadmin，但我发现URL中的某些地址与输入数据库的地址类似。

这是我的插入代码。谢谢

<?php

    include '../configuration/credentials.php';
    if($_SERVER['REQUEST_METHOD']=='POST'){
        $conn = mysqli_connect(DB_SERVER,DB_USER,DB_PASSWORD,DB_DATABASE);
        if($conn->connect_error){
            die("Connection failed: " . $conn->connect_error);
        }

        $firstname = $_POST["firstname"];
        $lastname = $_POST["lastname"];
        $dateofbirth = $_POST["dateofbirth"];
        $email = $_POST["email"];
        $phone = $_POST["phone"];
        $password = $_POST["password"];

        $firstname = mysqli_real_escape_string($conn,trim($firstname));
        $lastname = mysqli_real_escape_string($conn,trim($lastname));
        $dateofbirth = mysqli_real_escape_string($conn,trim($dateofbirth));
        $email = mysqli_real_escape_string($conn,trim($email));
        $phone = mysqli_real_escape_string($conn,trim($phone));
        $password = mysqli_real_escape_string($conn,trim($password));

        $checkuserexistsquery = "SELECT email, phone FROM users WHERE email='$email' AND phone='$phone'";
        $insertuserquery = "INSERT INTO users (firstname,lastname,dateofbirth,phone,email,password) VALUES ('$firstname','$lastname','$dateofbirth','$phone','$email','$password')";
        $checkuserexistsresults = mysqli_query($conn,$checkuserexistsquery);
        if($checkuserexistsresults===FALSE){
            echo "Check user query failed";
        }else{
            $countcheckuserexistsresults = mysqli_num_rows($checkuserexistsresults);
            if($countcheckuserexistsresults>0){
                //user already exists
                echo "User already exists";
                while($row = $checkuserexistsresults->fetch_assoc()){
                    echo $row['email'];
                    echo $row['phone'];
                }

            }else{
                //user doesn't exist
                $insertuserresults = mysqli_query($conn,$insertuserquery);
                if($insertuserresults===FALSE){
                    echo "Insert user query failed";
                }else{
                    echo "Insert successful";
                }
            }
        }
        mysqli_close($conn);
    }

?>

希望我能得到这方面的帮助