How to display posts on a separate page (not on the main page)?

Question

WordPress

Here on Habré and not only this question was asked and many more where it was explained.
But I don't understand why it doesn't work for me.
I created index.php and page-posts.php (template).
I go to the admin panel, create 2 pages: Main and Publications (I choose the page-posts.php template).
In the reading settings, I specify that the main page will be the static page "Home", and for the records I select "Publications".
I go to the "Publications" page and my main page opens. What is the problem?
I'm clearly missing something. Help understand.




index.php

file: page-posts.php file (it differs internally):

Answer 1

I don't know where you get all this from, but index.php is not the main one. index.php is the most basic template, it's used when WP can't find any other suitable
one For the main one you need to use front-page.php or home.php and the default template is generally page.php
Read the template hierarchy for details