I am unable to delete attached files from their folders programmatically or even through the wordpress admin as the admin user. The attachment record deletes from the database but the file remains in the folder.

I can retrieve that file successfully using

get_attached_media( 'application', $post_id )

I can delete the record using

wp_delete_attachment($post_id, true)

But this doesn't delete the file. I tried feeding the confirmed path of the file to wp_delete_file(), no luck

I tried to manually unlink

function delete_unattached_attachments($id){
    $attachments = get_posts( array(
    'post_type' => 'attachment',                        
    'numberposts' => -1, 
    'post_parent' => $id,
        ));                                 
        if ($attachments) {             
            foreach ($attachments as $attachmentID){
                $attachment_path = get_attached_file( $attachmentID->ID); 
                //Delete attachment from database only, not file
                $delete_attachment = wp_delete_attachment($attachmentID->ID, true);
                //Delete attachment file from disk
                $delete_file = unlink($attachment_path);                    
            }                   
        }               
}

I thought it was a capability at first but the admin can't even do it. I've tested on both localhost and live. Same deal. I check the read/write of the folder and I have delete priv.

The folders are json I add as application files for each post to hold chunks of data. I add them like so and they show correct parent in database.

$attachment = array(
    'guid'=> $wp_upload_dir['url'] .'/'. basename( $file ), 
    'post_mime_type' => 'application/json',
    'post_title' => $postTitle,
    'post_content' => $postTitle,
    'post_status' => 'inherit'
);
wp_insert_attachment($attachment, $file, $post_id);

Also the post parent of the attachment is a custom post type