First off, Can I just ask, what is it that relates the related post? Is it categories or something? I am wanting to put related posts on my home page which is a static page and nothing happens.
Having said that, I am using a child theme of notes-blog-core and whether I put the template files in the child or the parent theme folder I do not get an option for using the template files. I see the option but it's unclickable.
What I want to do is call the post thumbnails onto my home page.