Cannot update value in PHP - php

Question

I have a problem with updating value with PHP, it can get the data that I input but it cannot update it and render it to the read page.
<?php
require_once("session.php");
require_once("included_functions.php");
require_once("database.php");
new_header("VinceT");
$mysqli = Database::dbConnect();
$mysqli->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
if (($output = message()) !== null) {
echo $output;
}
echo "<h3>Update A Order</h3>";
echo "<div class='row'>";
echo "<label for='left-label' class='left inline'>";
if (isset($_POST["submit"])) {
$stmt = $mysqli->prepare("UPDATE VTCustomer SET CustomerFName=? WHERE CustomerID=?");
$stmt->execute([$_POST["CustomerFName"],$_POST["CustomerID"]]);
$stmt1 = $mysqli->prepare("UPDATE VTCustomer SET CustomerLName=? WHERE CustomerID=?");
$stmt1->execute([$_POST["CustomerLName"],$_POST["CustomerID"]]);
if($stmt) {
$_SESSION["message"] = $_POST["CustomerFName"]." has been updated";
} else {
$_SESSION["message"] = "Error! Could not update ".$_POST["CustomerFName"];
}
redirect("read.php");
} else {
if (isset($_GET["id"]) && $_GET["id"] !== "") {
$stmt = $mysqli->prepare("SELECT OrderID FROM OrderVinceT WHERE OrderID=?");
$stmt->execute([$_GET["id"]]);
if ($stmt) {
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
echo "<h3>Order ".$row["OrderID"]." Information</h3>";
}
echo "<form method='POST' action='update.php'>";
echo "<input type = 'hidden' name = 'OrderID' value = ' ".$row['OrderID']." ' />";
$stmt1 = $mysqli->prepare("SELECT CustomerFName FROM VTCustomer WHERE CustomerID=?");
$stmt1->execute([$_GET["id"]]);
if ($stmt1) {
while ($row1 =$stmt1 -> fetch(PDO::FETCH_ASSOC)) {
echo "<p>Customer First Name: <input type='text' name='CustomerFName' value='".$row1["CustomerFName"]."'></p>";
}
}
$stmt5 = $mysqli->prepare("SELECT CustomerLName FROM VTCustomer NATURAL JOIN OrderVinceT WHERE OrderVinceT.CustomerID=?");
$stmt5->execute([$_GET["id"]]);
if ($stmt5) {
while ($row5 =$stmt5 -> fetch(PDO::FETCH_ASSOC)) {
echo "<p>Customer Last Name: <input type='text' name='CustomerLName' value='".$row5["CustomerLName"]."'></p>";
}
}
echo "<input type='submit' name='submit' value='Update Order' class='tiny round button'/>";
echo "</form>";
echo "<br /><p>&laquo:<a href='read.php'>Back to Main Page</a>";
echo "</label>";
echo "</div>";
} else {
$_SESSION["message"] = "Order could not be found!";
redirect("read.php");
}
}
}
new_footer("VinceT");
Database::dbDisconnect($mysqli);
?>
Do you guys have any idia why I cannot update this? I test queries in the console and it works just fine. The if statement that render out the message still receive the value of the input but it cannot update the database that render out in read.php