Search Result Not Displaying Some Pages

I have installed wordpress and created theme but my default wordpress
search function is not displaying some page even though I use same keyword as page title in search box. What might be the cause for it?

My Searchform.php code looks like below:

<div class="searchform search" rol="search">

 <form method="get" id="searchform" action="<?php bloginfo('url'); ?>/">

        <input type="search" value="<?php the_search_query(); ?>" name="s" id="s" placeholder="<?php echo get_theme_mod('search_placeholder', 'Search: Enter Your keywords'); ?> "/>

        <input type="submit" class="sbutton" alt="Search" value="search"/>

    </form>

</div>

My search.php code looks like below:

<?php dynamic_sidebar('header-link'); ?>
                <div class="clear" style="clear:both; width:100%; height:auto;"></div>
<div class="content">
<?php dynamic_sidebar('mobile-widget'); ?>
    <div class="mainbar">

        <?php the_post(); ?>

        <div class="article">
            <?php if (is_active_sidebar('sidebar-1')) : ?>
                <div id="secondary" class="widget-area" role="complementary">
                    <?php dynamic_sidebar('sidebar-1'); ?>
                </div><!-- #secondary -->
            <?php endif; ?>

          <?php if ( have_posts() ) : ?>

                <h1 class="page-title"> <?php  echo get_theme_mod('search_result_text', 'Search Results Found For'); ?> <span><?php the_search_query(); ?></span></h1>

<?php while ( have_posts() ) : the_post() ?>

                <div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
                    <h2 class="entry-title"><a href="<?php the_permalink(); ?>" title="<?php printf( __('Permalink to %s', 'evotis'), the_title_attribute('echo=0') ); ?>" rel="bookmark"><?php echo get_post_meta($post->ID, '_yoast_wpseo_title', true); ?></a></h2>

                    <div class="entry-summary">
<?php echo get_post_meta($post->ID, '_yoast_wpseo_metadesc', true); ?>
                 <div class="h-readmore"> <a href="<?php the_permalink(); ?>"><?php echo get_theme_mod('readmore', 'Lees artikel'); ?></a></div>
                    </div><!-- .entry-summary -->

                </div><!-- #post-<?php the_ID(); ?> -->

<?php endwhile; ?>

<?php global $wp_query; $total_pages = $wp_query->max_num_pages; if ( $total_pages > 1 ) { ?>
                <div id="nav-below" class="navigation">
                    <div class="nav-previous"><?php next_posts_link(__( '<span class="meta-nav">&laquo;</span> Older posts', 'evotis' )) ?></div>
                    <div class="nav-next"><?php previous_posts_link(__( 'Newer posts <span class="meta-nav">&raquo;</span>', 'evotis' )) ?></div>
                </div><!-- #nav-below -->
<?php } ?>            

<?php else : ?>

                <div id="post-0" class="post no-results not-found">
                    <h2 class="entry-title"><?php _e( 'Nothing Found', 'evotis' ) ?></h2>
                    <div class="entry-content">
                        <p><?php _e( 'Sorry, but nothing matched your search criteria. Please try again with some different keywords.', 'evotis' ); ?></p>
    <?php get_search_form(); ?>
                    </div><!-- .entry-content -->
                </div>

<?php endif; ?>   

            <?php if (is_active_sidebar('sidebar-2')) : ?>
                <div id="secondary" class="widget-area" role="complementary">
                    <?php dynamic_sidebar('sidebar-2'); ?>
                </div><!-- #secondary -->
            <?php endif; ?>
        </div>
    </div>
    <?php get_sidebar(); ?>
    <div class="clr"></div>
</div>
</div>
<?php get_footer(); ?>