custom user order

https://www.knowingimmigrationlaw.com/contributors/

The client has requested a custom order to the list of contributors. Not alpha-numeric like originally used. This is what I’ve done:

Installed the Advanced Custom Fields Plugin by Elliot Condon and created a field that is named “rank”. It is a dropdown list with the numbers 1-8. It is only assigned to users that equal “author” with no default value.

Then, I assigned each user the ranking they were requested. Lastly, in my template file I used the following code:

<?php 

$allUsers = get_users('meta_key=rank&order=DESC');

$users = array();

// Remove subscribers from the list as they won't write any articles
foreach($allUsers as $currentUser)
{
	if(!in_array( 'subscriber', $currentUser->roles ))
	{
		$users[] = $currentUser;
	}
}

?>

On my local testing machine, this works perfectly. On the server I uploaded it to, I get a random listing which is being shown.

Any help would be appreciated. Thanks.