PHP - Page doesn't redirect after form is submitted

Question

I can't get my page to redirect once the login form is submitted. I've seen other Q&A pages on here and it seems like I am doing it correctly according to their suggestions but I don't know why it's not working.

I tested it on XXAMP and it worked fine there, but once I uploaded it to my site it stopped working (the page does not redirect back to index.php.

I am getting logged in, and I can ensure this because once I log in and get sent to the blank page, I can go to the address bar and enter the site name again, and it will show me that I am logged in.

I'd appreciate any help!

Thanks!

This is my index.php page:

<!--This is my index.php page-->
<?php
include 'includes/header.php';
?>

<div class = "container">
    <div class = "container-fluid">
        </div>

            <?php
            if (isset($_SESSION['uid'])) {
                echo "<div class = 'loggedin'>
                        <p>You are logged in as " . $_SESSION['uid'] . ".</p>";
                echo "<div class = 'date'>Today is ";
                        $dayofweek = date("w");
                        //echo $dayofweek;
                        switch ($dayofweek) {
                            case 1:
                                echo "Monday";
                            break;
                            case 2:
                                echo "Tuesday";
                            break;
                            case 3:
                                echo "Wednesday";
                            break;
                            case 4:
                                echo "Thursday";
                            break;
                            case 5:
                                echo "Friday";
                            break;
                            case 6:
                                echo "Saturday";
                            break;
                            case 0:
                                echo "Sunday";
                            break;
                        }

                        $fulldate = date(", F jS, Y.");
                        echo $fulldate .
                        "</div></div>" .
                        "<p>Welcome, " .
                        $_SESSION['fname'].
                        "!</p>" .
                        "<div class = 'profilephoto'></div>";
            }
            else {
                echo "<div class = 'main'>
                    <p>Sign up below to start using this free site!</p>
                </div>
                <div class = 'signinform'><form action = 'includes/login.php' method = 'POST'>
                    <label for = 'uid'>Username: </label>
                    <input type = 'text' name = 'uid' placeholder = 'Username'>
                    <br>
                    <label for = 'pwd'>Password: </label>
                    <input type = 'password' name = 'pwd' placeholder = 'Password'>
                    <br>
                    <button type = 'submit'>Sign In</button>
                </form>
                <div class = 'joinnowbutton'><p>Not a member? <a href = 'joinnowpage.php'>Join Now</a></p></div></div>";
                }
            ?>
    </div>
</div>

And this is my login.php page:

<!--This is my login.php page-->
<?php
session_start();
include '../dbh.php';
?>

<?php
$inputuser = mysqli_real_escape_string($conn, $_POST['uid']);
$inputpass = mysqli_real_escape_string($conn, $_POST['pwd']);


if (empty($inputuser) || (empty($inputpass))) {
    echo "Invalid username or password.";
    die();
}

$sql = "SELECT * FROM users WHERE uid = '$inputuser' AND pwd = '$inputpass'";


$result = $conn->query($sql);

if ($row = mysqli_fetch_assoc($result)){

    $_SESSION['uid'] = $row['uid'];
    $_SESSION['fname'] = $row['fname'];
    $_SESSION['lname'] = $row['lname'];
    $_SESSION['city'] = $row['city'];
    $_SESSION['state'] = $row['state'];
    $_SESSION['uid'] = $row['uid'];

    header("Location:../index.php");
}
else {

    header("Location:/fail.php");
}

$conn->close();
?>