Bxslider breaking after leaving page

Question

I wonder if anyone could help me with a problem I am having with bxslider. I am creating a Wordpress site and using the jQuery bxslider instead of the plugin version. Everything with the slider is fine when you load the website, but when you leave the homepage to go to another page, and then come back the slider is broken.

When I say broken, both slides are showing and the JavaScript has stopped. Im using Bootstrap 3 as the framework of the theme.

I'm not used to posting on here, so sorry if I have made a mistake please feel free to correct it.

Any help would be appreciated.

Many Thanks

<div class="container">     
     <section class="row" id="slidercontainer">
           <div class="col-lg-12 col-md-12 col-sm-12 col-xs-12" id="sliderholder">
             <ul class="bxslider">
                <?php
                    global $post;
                    $args = array('numberposts' => 4, 'category' => 2, 'post_status'=>"publish");
                    $myposts = get_posts($args);
                    foreach($myposts as $post) : setup_postdata($post);
                                        ?>
                <li id="post-<?php the_ID(); ?>" class="slider-item">
                    <h1><?php echo get_the_title();?></h1>
                    <?php 
                        $imageArray = get_field('slider_image'); // Array returned by Advanced Custom Fields
                        $imageAlt = $imageArray['alt']; // Grab, from the array, the 'alt'
                        $imageThumbURL = $imageArray['sizes']['postslider']; //grab from the array, the 'sizes', and from it, the 'thumbnail'
                    ?>
                    <img class="pull-right" src="<?php echo $imageThumbURL;?>" alt="<?php echo $imageAlt; ?>">
                    <?php
                        $content = apply_filters( 'the_excerpt', get_the_excerpt() );
                        $content = str_replace( ']]>', ']]&gt;', $content );
                    ?>
                    <div class="slider-content"><?php echo $content;?></div>
                </li>
                <?php
                    endforeach;
                    wp_reset_postdata();
                ?>
            </ul>
        </div>
     </section>
    </div>

<!-- JavaScript -->
$(document).ready(function(){
        $('.bxslider').bxSlider({
            maxSlides: 4,
            pager: false,
            auto: true,
            autoHidePager: true,
            pause: 10500,
            controls: true,
            speed: 1800,
            mode: 'horizontal'
        });
    });