A custom shortcode on bottom of the page, populates the markup on top

I am using the enfold theme for the first time, and I really love this theme.
I see that this theme comes with a feature to display the testimonials. I really like the way the testimonials are being displayed in the default grid. But they are all static content.

On my website though, I want to have testimonials as a custom post type. I want to display every individual testimonial on its own page when I click on the person’s name, or picture or a Read More link.
I created a custom post type called “Testimonials” using “CPT UI” plugin.
In order to use exactly the same markup and styling that comes with the default testimonials in Enfold theme, I tried creating a shortcode for my custom post type “Testimonials” in function.php.
I want to dynamically pull 4 testimonials that belong to the category “Home”, and display them on the homepage using the shortcode.

I wrote the following function in functions.php to create the shortcode:

/* SHORT CODE FOR TESTIMONIALS GRID ON HOME PAGE */
function home_testimonials_shortcode() {
	$loop = new WP_Query( array( 'post_type' => 'testimonial', 'category_name' => 'home', 'posts_per_page' => '4' ) );
    
	if ( $loop->have_posts() ) {
        
        $output = '';
		while ( $loop->have_posts() ) { 
            $loop->the_post();

            $post_thumbnail_id = get_post_thumbnail_id( $post_id );
            $testimonial_permalink = get_permalink( $post_id );
            $excerpt = get_the_excerpt( $post_id );
            $testimonialTitle = get_the_title();
            $output .= "[av_testimonial_single href=" . $testimonial_permalink . " src=". $post_thumbnail_id ." name=". $testimonialTitle ." subtitle='Product Owner' link='http://' linktext='']";
            $output .= $excerpt . "... <a href=" . $testimonial_permalink . ">Read More</a>";
            $output .= "[/av_testimonial_single]";
        }
        echo do_shortcode("[av_testimonials style='grid' columns='2' grid_style='' interval='5' font_color='' custom_title='' custom_content='' admin_preview_bg='']". $output ."[/av_testimonials]");
	}
	
    	
};
add_shortcode('testihome', 'home_testimonials_shortcode');

I see that the testimonials (from my custom post type) are now being dynamically pulled and are displaying perfectly fine on the home page.
For some reason though, I see all the Testimonials appear on top of the page.
I am putting my custom shortcode to display the testimonials on the bottom of my home page. I am putting my shortcode [testihome] in a “Text Block” element inside a “Full-Width Layout” element, on the bottom of my homepage. But for some reason, the testimonials are displayed on top of the page.
Is there something I am missing somewhere. Please help. Thanks