Flexslider is not showing - Building Custom Wordpress Theme

Hello,

I created my custom wordpress theme following the video tutorials but my flexslider isn't showing up. It shows up ONLY when I exclude this bit of php code (which is the code to add a project after I click Yes on a checkbox):

<?php $display = get_field('display_on_slider'); if( $display[0] == "Yes" ) : ?>

I renamed the checkbox custom field to: "display-on-slider" instead of display on homepage & I renamed the homepage slide image to "slider-image", but I don't see renaming my custom fields as the problem.

Also, I placed my flexslider in the "Portfolio" page (work.php) not in the frontpage.

Here is my website/url

and this is the code on my Portfolio page:

```html

<?php

/* Template Name: Work Page */

get_header(); ?>

<p><a href="<?php echo get_permalink( 80 ); ?>">Home</a> >> <strong>Portfolio</strong></p> <hr>

<div id="featured" class="clearfix flexslider"> <ul class="slides"> <?php $args = array ( 'post_type' => 'work' ); $the_query = new WP_Query( $args ); ?>

    <?php if ( have_posts() ) : while ( $the_query->have_posts() ) : $the_query->the_post(); ?>
    <?php $display = get_field('display_on_slider'); if( $display[0] == "Yes" ) : ?>
        <li>
            <div class="container">
                <div class="grid_8">
                    <img src="<?php the_field( 'slider_image' ); ?>" alt="<?php the_title(); ?> Project Screenshot">
                </div>
                <div id="featured-info" class="grid_4 omega">
                    <h3><?php the_title(); ?></h3>
                    <p><?php the_field( 'description' ); ?></p>
                    <a class="btn" href="<?php the_permalink(); ?>">View Project</a>
                </div>
            </div>
        </li>
    <?php endif; ?>
    <?php endwhile; endif; ?>
</ul>

</div>

<?php get_template_part( 'content', 'testimonials' ); ?>

<?php get_footer(); ?> ```