WordPress loop collapses HTML after 61st post

I’m running a WordPress WP_GeoQuery to pull posts within a custom post type by location with no problem. However, the loop breaks the rest of the HTML on the page including the sidebar & footer. I played around with the ‘posts_per_page’ option and it appears that WordPress dies after the 61st (random number I know) post.

I realise that it can be paginated which will fix the issue and I will do this, but curiosity has got the better of me and it’s bugging me not knowing why. I’ve had a search around Google but couldn’t find any answers.

So, I basically wanted to know if WordPress has a limit of 61 posts set somewhere or if I’m doing something really silly that is breaking it? Code below..

Thanks for any help in advance!

<?php // get location of user
    $url = "http://freegeoip.net/json/". $_SERVER['REMOTE_ADDR'] .'';
    $geo = json_decode(file_get_contents($url), true);

    // store lat and long of user location
    $Slat = $geo[latitude];
    $Slng = $geo[longitude];
?>

<?php $args = array(
    'post_type' => 'event',
    'latitude' => $Slat,
    'longitude' => $Slng,
    'author'=> $user_id,
    'posts_per_page' => 61
    )
?>


    <?php $the_query = new WP_GeoQuery( $args ); ?>

        <?php $plus = 0; ?>
        <?php foreach( $the_query->posts as $post ) : ?>

        <?php $postid = get_the_ID(); ?>

            <div class="event clearfix">

                <div class="event-image grid-1-4 no-padding">

                    <?php $images = get_field('images'); ?>
                        <img src="<?php echo $images[0][sizes][thumbnail]; ?>" alt="<?php the_title(); ?>" />

                </div>

                <div class="event-info grid-1-2">

                    <h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
                    <form action="/edit-event" method="POST">
                        <input type="hidden" value="<?php echo $postid; ?>" name="id" />
                        <input type="submit" class="edit-button" value="edit event" />
                    </form>

                </div>

                <div class="event-details grid-1-4 no-padding">

                    <div class="detail">Distance <?php echo round($post->distance, 1); ?> mi</div>
                    <div class="detail">Price: &pound;<?php the_field('adult'); ?></div>

                    <?php include('countdown.php'); ?>

                </div>



            </div>

            <?php $plus++; ?>

    <?php endforeach; ?>