Uploading chunked files to s3 with php

I have a php script where I store a file uploaded by the user in a tmp folder and then move it to s3. I also check if the emails they entered are valid in the database. I am using chunking so that large files can get uploaded to the server quickly. My post_max_size is 8M, however I am only able to upload files that are very small. If I upload a 7M file, it doesn't work. Am I doing something incorrectly? I'm fairly new to php so I'd appreciate the help!

This is my ajax call to the php file:

$.ajax({
    type: "POST",
    url: "../FileDrop/dbSystem.php",
    cache: false,
    processData: false,
    contentType: false,
    data: formData,
    success: function(result) {
        result = JSON.parse(result);
        if (result.validity === "valid emails") {
            resetInputs();
            location.reload();
            $(".outputDiv").show();
        }
        else if (result.validity === "invalid emails") {
            var tagsBrackets = result.emails.toString().replace(/[\[\]']+/g, '');
            var tagsQuotes = tagsBrackets.replace(/['"]+/g, '');
            var tagsInvalid = tagsQuotes.replace(/,/g, ", ");
            $('#alertModal').modal({show:true});
            document.getElementById('invalid').textContent = tagsInvalid;
        }
        else {
            $('#alertModalFile').modal({show:true});
            document.getElementById('userFile').value = null;
        }
    }
});

This is my dbSystem.php file:

<?php
//ini_set('post_max_size', '1024M');
//ini_set('upload_max_filesize', '1024M');

$thisPage = "dbSystem.php";
include_once 'validateAccess.php';
include_once "../Resources/s3Functions.php";

$output = [];

$fileName = $_FILES['file']['name'];
$currentUserID = $userID;
$currentUserEmail = $userEmail;

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

// create connection
$conn = new mysqli($servername, $username, $password, $db);

$tags = json_decode($_POST['tags']);
$result = 'SELECT distinct email_address FROM nva_users where email_address in (?' . str_repeat(',?', count($tags) - 1) . ') and is_active = "Y"';
$rows = $conn->prepare($result);

// bind values from $tags to the query
$rows->bind_param(str_repeat('s', count($tags)), ...$tags);
// execute
$rows->execute();
// bind a variable for the result
$rows->bind_result($email);

// retrieve the emails in a new array
$dbMails = [];
while ($rows->fetch()) {
    $dbMails[] = $email;
}

// retrieve ids of users in a new array
$receiverIds = [];
foreach ($dbMails as $mails) {
    $dbIds = "SELECT id FROM nva_users where email_address='$mails'";
    $queryResult = mysqli_query($conn, $dbIds);
    while ($row = $queryResult->fetch_row()) {
        $receiverIds[] = $row;
    }
}
// anything that's in $tags but not in $dbMails is invalid
$invalidEmails = array_diff($tags, $dbMails);
if ($invalidEmails) {
    $output["validity"] = "invalid emails";
    $output["emails"] = array_values($invalidEmails);
} else {
    $output["validity"] = "valid emails";
    $receiverIds = str_replace(array('[', ']'), '', str_replace(array('"', '"'), '', str_replace(array(','), ', ', json_encode($receiverIds))));;
    $mailInsert = str_replace(array('[', ']'), '', str_replace(array('"', '"'), '', str_replace(array(','), ', ', json_encode($dbMails))));
    $insertQuery = "INSERT INTO filedrop_logs (sender_id, sender_email, receiver_ids, receiver_emails, file_name, s3_upload_status) VALUES ('$currentUserID', '$userEmail', '$receiverIds', '$mailInsert', '$fileName', 'N')";

    $sql = "DELETE FROM filedrop_logs WHERE sender_id='$currentUserID'";

    if (mysqli_query($conn, $insertQuery)) {
        getAffectedRows($conn);
    }    
}

if(array_key_exists('file', $_FILES)) {
    if ($_FILES['file']['error'] === UPLOAD_ERR_OK) {
        if ($_FILES['file']['size'] <= ini_get('post_max_size')) {
            if (isset($_POST) && $output["validity"] === "valid emails") {
                $fileName = basename($_FILES["file"]["name"]);
                $error = $_FILES["file"]["error"];
                $tmpName = $_FILES["file"]["tmp_name"];

                if (isset($_FILES["fileName"]) && $fileName != '' && $tmpName != '' && file_exists(sys_get_temp_dir())) {
                    $separator = DIRECTORY_SEPARATOR;
                    $newDir = sys_get_temp_dir() . $separator . "FileDrop" . microtime(true);

                    if (!file_exists($newDir)) {
                        mkdir($newDir, 0777, true); // creates temp FileDrop directory
                        $tempFilePath = $newDir . $separator . $fileName; // creates temp file inside FileDrop directory

                        // dealing with the chunks
                        $chunk = isset($_REQUEST["chunk"]) ? intval($_REQUEST["chunk"]) : 0;
                        $chunks = isset($_REQUEST["chunks"]) ? intval($_REQUEST["chunks"]) : 0;
                        $out = @fopen("{$tempFilePath}.part", $chunk == 0 ? "wb" : "ab");

                        if ($out) {
                            $in = @fopen($tmpName, "rb");
                            if ($in) {
                                while ($buff = fread($in, 4096)) {
                                    fwrite($out, $buff);
                                }
                            } else {
                                verbose(0, "Failed to open input stream");
                            }
                            @fclose($in);
                            @fclose($out);
                            //deleteDir($newDir);
                        } else {
                            verbose(0, "Failed to open output stream");
                        }
                        // check if file was uploaded
                        if (!$chunks || $chunk == $chunks - 1) {
                            rename("{$tempFilePath}.part", $tempFilePath);
                            $s3FileName = "FileDrop" . substr($newDir, 4) . $separator . $fileName;
                            $result = putFileToS3($s3FileName, $tempFilePath, 'public-read');
                            deleteDir($newDir);
                        }
//                        verbose(1, "Upload OK");
                    }
                }
            }
        }
        else {
            $output = "Upload failed";
        }
    }
    else {
        $output = "Upload failed";
    }
}
else {
    $output = "Upload failed";
}

// the response function
function verbose($ok = 1, $info = "")
{
    // failure to upload throws 400 error
    if ($ok == 0) {
        http_response_code(400);
    }
    die(json_encode(["ok" => $ok, "info" => $info]));
}

function deleteDir($dirPath)
{
    if (!is_dir($dirPath)) {
        if (file_exists($dirPath) !== false) {
            unlink($dirPath);
        }
        return;
    }
    if ($dirPath[strlen($dirPath) - 1] != '/') {
        $dirPath .= '/';
    }
    $files = glob($dirPath . '*', GLOB_MARK);
    foreach ($files as $file) {
        if (is_dir($file)) {
            deleteDir($file);
        } else {
            unlink($file);
        }
    }
    rmdir($dirPath);
}

echo json_encode($output);
?>

source https://stackoverflow.com/questions/67942300/uploading-chunked-files-to-s3-with-php