Thank you for your help, but what i realized is that whenever you put “Automatically append to the post content” to “false”, my related pages disappear. Now with your modified code, i changed my single.php, there is no related pages in the page. I mean don’t appear anywhere.
What is going on?
Am i doing something wrong? Maybe i am changing the modified code incorrectly? In my wordpress i am going to Appearance > Editor > Single.pho > Copy Pase you modified code > Update
Is that correct?
Thank you for your answer. About the second question i solved it by uploading featured photos on every page i need and deactivating the option in my theme that shows the featured pictures. And it worked!