wp_nav_menu broken hierarchy when fetched with jQuery AJAX

Please help, I’ve been pulling my hair for days now.

My wp_nav_menu (with custom walker) output gets scrambled in the returned data via jQuery AJAX calls.

My wp_nav_menu returned via ajax looks like this:

<div class="container">
    <div id="page" class="hfeed row">
        <div id="gssHeader" class="span12">
            <div id="gss-menu">
                <div id="gss-menu-1" class="gss-menu-item"></div>
                <a href="https://localhost/gs2/">Home</a>
            </div>
            <div id="gss-menu-2" class="gss-menu-item"></div>
            <a href="https://localhost/gs2/about/">About</a>
        </div>
        <div id="gss-menu-3" class="gss-menu-item"></div>
        <a href="https://localhost/gs2/contact/">Contact</a>
    </div>
</div></div>

The hierarchy is completely broken. On a fresh page load without ajax, the menu looks normal like this:

<div class="container">
    <div id="page" class="hfeed row">
        <div id="gssHeader" class="span12">
            <div id="gss-menu">
                <div id="gss-menu-1" class="gss-menu-item">
                    <a href="https://localhost/gs2/">Home</a>
                </div>
                <div id="gss-menu-2" class="gss-menu-item">
                    <a href="https://localhost/gs2/about/">About</a>
                </div>
                <div id="gss-menu-3" class="gss-menu-item">
                    <a style="cursor: pointer;">Contact</a>
                </div>
            </div>
        </div>

Using the template’s prepackaged menu and walker works normally, but the one I created for my needs doesn’t. I’m a PHP novice, and pieced this code from other posts online. It gives me the structure I need for a fresh page load, just not using AJAX.

<?php wp_nav_menu( array(
    'theme_location'=>'primary',
    'menu_class'=>  'gssHeader nav',
    'depth' =>0,
    'items_wrap'=>'<div id="gss-menu">%3$s</div>',
    'container'=>false,
    'walker'=>new GSS_Walker
) ); ?>

GSS_Walker:

class GSS_Walker extends Walker_Nav_Menu {
    var $number = 1;

    function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
        $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

        $class_names = $value = '';
        $classes = array();
        $classes[] = 'gss-menu-item';
        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
        $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
        $id = apply_filters( 'nav_menu_item_id', 'gss-menu-'. $this->number++, $item, $args );
        $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
        $output .= $indent . '<div' . $id . $value . $class_names .'/>';

        $atts = array();
        $atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
        $atts['target'] = ! empty( $item->target )     ? $item->target     : '';
        $atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';
        $atts['href']   = ! empty( $item->url )        ? $item->url        : '';
        $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );
        $attributes = '';
        foreach ( $atts as $attr => $value ) {
            if ( ! empty( $value ) ) {
                $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
                $attributes .= ' ' . $attr . '="' . $value . '"';
            }

Here’s the link if you want credit for the answer on StackOverflow:
https://stackoverflow.com/questions/21183580/wp-nav-menu-broken-hierarchy-when-fetched-with-jquery-ajax-wordpress

Thanks in advance.