PHP - Deleting folders won't work on some cases - php

Question

I have a folder with subfolders containing all kind of files..
When I trigger action to delete them, some of them got deleted but some of them don't. What I am trying to say is that they are all pretty much same structure.. I don't know what is causing that? Is it something with timing or? I am deleting the folder with files once the zip files are created.
This is the method which is deleting folder with subfolders and files..
private function removeFiles($name)
{
// Locate folder to remove
$rootDirElements = [
$this->kernel->getProjectDir(),
$name
];
$rootDir = implode(DIRECTORY_SEPARATOR, $rootDirElements);
$rdi = new RecursiveDirectoryIterator($rootDir, RecursiveDirectoryIterator::SKIP_DOTS);
$files = new RecursiveIteratorIterator(
$rdi,
RecursiveIteratorIterator::CHILD_FIRST
);
foreach ($files as $file) {
if ($file->isDir()) {
rmdir($file->getRealPath());
} else {
unlink($file->getRealPath());
}
}
rmdir($rootDir);
}
And I am calling it in another method where zip logic is happening:
private function zipFolder($source, $destination, $name, $includeDir = false)
{
$zip = new ZipArchive();
if ($zip->open($destination, ZipArchive::CREATE | ZipArchive::OVERWRITE) === true) {
//zipping logic
}
}
}
}
$zip->close();
// After zip file is created delete folder
$this->removeFiles($name);
I don't know what is causing that?