WordPress sticky Post issue

Solution for WordPress sticky Post issue
is Given Below:

I am trying so long to show sticky post at first then the rest of the post, just one time it was working after then no more working. i tried many way but not working. I think my query has a problem.

      $args = array(
                    'category_name' => 'case-studies',
                    'post_type' => 'post',
                    'include_sticky_posts' => 1,
                $query = new WP_Query( $args );
                if ( $query->have_posts() ) {
                    while ( $query->have_posts() ) {

                        <?php $url = wp_get_attachment_url( get_post_thumbnail_id($post->ID), 'full' ); ?>

                <div class="case-studies <?php echo join(', ', array_map(function($t) { return $t->name; }, get_the_tags())); ?>">

                    <div class="case-content">
                        <h2><?php the_title(); ?></h2>

                        <p><?php the_excerpt(); ?><span class="btnMore"><a href="<?php the_permalink(); ?>">READ MORE</a></span></p>

                        <?php if( get_field('testimonial_name') ): ?>

                        <div class="persondeatils"> <img src="<?php the_field('testimonial_image'); ?>" alt="<?php the_title(); ?>"> <span><?php the_field('testimonial_name'); ?></span></div>

                        <?php endif; ?>


                    <div class="case-thumbnail" style="background-image: url(<?php if (get_field( 'big_thumbnail' ) ): ?><?php the_field('big_thumbnail'); ?>
<?php else:  ?><?php echo $url ?><?php endif;  ?>);"><a href="<?php the_permalink(); ?>"></a></div>

} else {

I tried with include_sticky_posts' => true/false i have no idea how it was working one time but without touch my code it is not working.