My worpress search page is showing no results

I want to display the publications searched for via searchform.php in the search.php page but it does not work …

The search is done well when I look at the url (ex: New World):
http://localhost/?post_type=post&s=New+World

But I have nothing displayed on the results page, I fall directly into the else.

Here is my code:

                    <?php if (have_posts()) : ?>
                        <?php while (have_posts()) : the_post(); ?>
                            <?php get_template_part('content', 'search'); ?>
                            <?php include("assets/php/posts.php"); ?>
                        <?php endwhile; ?>
                    <?php else : ?>
                      ...
                    <?php endif; ?>

Thank you in advance for your help !