PHP ZipArchive failed to create zip file larger than 10 MB - php

Question

I am trying to create zip archive of user folder which contain files and folders. I am using WordPress and Apache server. Furthermore, I have mounted S3 bucket on the WordPress upload folder. The code is working perfectly when I try to generate zip outside mounted s3 bucket folder, and zip size is less than 10mb, but if it exceeds 10mb, zip get corrupted and 0kb file is generated. I have increase post_max_size to 1000M and memory_limit to -1, max_execution_time to 3600.
To mount s3 bucket I have used S3FS
My code:
$zip = new ZipArchive();
//$zip->open($zip_filename, ZipArchive::CREATE | ZipArchive::OVERWRITE);
if ($zip->open($zip_filename, ZipArchive::CREATE) !== true) {
exit("cannot open <$zip_filename>\n");
error_log('connot open ' . $zip_filename);
}
createZip($zip,$rootPath);
$status=$zip->getStatusString();
error_log('status: '.print_r($status, true));
$zip->close();
if (file_exists($zip_filename)) {
ob_clean();
ob_end_flush(); // more important function - (without - error corrupted zip)
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header('Content-Type: application/zip;\n');
header("Content-Transfer-Encoding: Binary");
header("Content-Disposition: attachment; filename=\"".basename($zip_filename)."\"");
header('Content-Length: ' . filesize($zip_filename));
readfile($zip_filename);
unlink($zip_filename);
}
function createZip($zip,$dir){
if (is_dir($dir)){
if ($dh = opendir($dir)){
while (($file = readdir($dh)) !== false){
// If file
if (is_file($dir.$file)) {
if($file != '' && $file != '.' && $file != '..'){
error_log('file path: '.$dir.$file);
$zip->addFile($dir.$file);
}
}else{
// If directory
if(is_dir($dir.$file) ){
if($file != '' && $file != '.' && $file != '..'){
// Add empty directory
$zip->addEmptyDir($dir.$file);
$folder = $dir.$file.'/';
// Read data of the folder
createZip($zip,$folder);
}
}
}
}
closedir($dh);
}
}
}