WordPress Taxonomy Term meta not working with export and import

I have created a Taxonomy Meta Data for Custom Post Type and its working fine while saving, updating, editing etc. But its not working while importing or exporting with wordpress importer. Taxonomies meta data are not importing.

Here is the Code based on the Tutorial

<?php
if ( ! function_exists( 'register_cpt_houses' ) ) {
    function register_cpt_houses() {
        $labels = array(
            'name'              => __('houses', 'my_plugin'),
            'singular_name'     => __('houses', 'my_plugin'),
            'add_new'           => __('Add New','my_plugin'),
            'add_new_item'      => __('Add New Slide','my_plugin'),
            'edit_item'         => __('Edit houses','my_plugin'),
            'new_item'          => __('New houses','my_plugin'),
            'view_item'         => __('View houses','my_plugin'),
            'search_items'      => __('Search houses','my_plugin'),
            'not_found'         => __('No houses found','my_plugin'),
            'not_found_in_trash'=> __('No houses found in Trash','my_plugin'),
            'parent_item_colon' => '' ,
            'all_items' =>  __( 'All houses' ,'my_plugin')
        );

        $args = array(
            'labels'            => $labels,
            'public'            => true,
            'exclude_from_search'=> false,
            'show_ui'           => true,
            'capability_type'   => 'post',
            'hierarchical'      => false,
            'rewrite'           => array('slug'=>'houses', 'with_front' => true ),
            'query_var'         => false,
            'menu_position'     => null,
            'supports'          => array('title', 'thumbnail', 'page-attributes')
        );

        register_post_type('houses',$args);
    }
    add_action('init', 'register_cpt_houses');
}
function register_feature_taxonomy() {
    $labels = array(
        'name' => _x( 'Features', 'taxonomy general name', 'my_plugin' ),
        'singular_name' => _x('Features', 'taxonomy singular name', 'my_plugin'),
        'search_items' => __('Search Feature', 'my_plugin'),
        'popular_items' => __('Common Features', 'my_plugin'),
        'all_items' => __('All Features', 'my_plugin'),
        'edit_item' => __('Edit Feature', 'my_plugin'),
        'update_item' => __('Update Feature', 'my_plugin'),
        'add_new_item' => __('Add new Feature', 'my_plugin'),
        'new_item_name' => __('New Feature:', 'my_plugin'),
        'add_or_remove_items' => __('Remove Feature', 'my_plugin'),
        'choose_from_most_used' => __('Choose from common Feature', 'my_plugin'),
        'not_found' => __('No Feature found.', 'my_plugin'),
        'menu_name' => __('Features', 'my_plugin'),
    );

    $args = array(
        'hierarchical' => false,
        'labels' => $labels,
        'show_ui' => true,
    );

    register_taxonomy('house_feature','houses', $args);
}
add_action( 'house_feature_add_form_fields', 'add_feature_group_field', 10, 2 );
function add_feature_group_field($taxonomy) {
    global $feature_groups;
    ?><div class="form-field term-group">
        <label for="featuret-group"><?php _e('Feature Group', 'my_plugin'); ?></label>
        <select class="postform" id="equipment-group" name="feature-group">
            <option value="-1"><?php _e('none', 'my_plugin'); ?></option><?php foreach ($feature_groups as $_group_key => $_group) : ?>
                <option value="<?php echo $_group_key; ?>" class=""><?php echo $_group; ?></option>
            <?php endforeach; ?>
        </select>
    </div><?php
}
add_action( 'created_house_feature', 'save_feature_meta', 10, 2 );

function save_feature_meta( $term_id, $tt_id ){
    if( isset( $_POST['feature-group'] ) && '' !== $_POST['feature-group'] ){
        $group = sanitize_title( $_POST['feature-group'] );
        add_term_meta( $term_id, 'feature-group', $group, true );
    }
}
add_action( 'house_feature_edit_form_fields', 'edit_feature_group_field', 10, 2 );

function edit_feature_group_field( $term, $taxonomy ){

    global $feature_groups;

    // get current group
    $feature_group = get_term_meta( $term->term_id, 'feature-group', true );

    ?><tr class="form-field term-group-wrap">
        <th scope="row"><label for="feature-group"><?php _e( 'Feature Group', 'my_plugin' ); ?></label></th>
        <td><select class="postform" id="feature-group" name="feature-group">
            <option value="-1"><?php _e( 'none', 'my_plugin' ); ?></option>
            <?php foreach( $feature_groups as $_group_key => $_group ) : ?>
                <option value="<?php echo $_group_key; ?>" <?php selected( $feature_group, $_group_key ); ?>><?php echo $_group; ?></option>
            <?php endforeach; ?>
        </select></td>
    </tr><?php
}
add_action( 'edited_house_feature', 'update_feature_meta', 10, 2 );

function update_feature_meta( $term_id, $tt_id ){

    if( isset( $_POST['feature-group'] ) && '' !== $_POST['feature-group'] ){
        $group = sanitize_title( $_POST['feature-group'] );
        update_term_meta( $term_id, 'feature-group', $group );
    }
}

add_filter('manage_edit-house_feature_columns', 'add_feature_group_column' );

function add_feature_group_column( $columns ){
    $columns['feature_group'] = __( 'Group', 'my_plugin' );
    return $columns;
}
add_filter('manage_house_feature_custom_column', 'add_feature_group_column_content', 10, 3 );

function add_feature_group_column_content( $content, $column_name, $term_id ){
    global $feature_groups;

    if( $column_name !== 'feature_group' ){
        return $content;
    }

    $term_id = absint( $term_id );
    $feature_group = get_term_meta( $term_id, 'feature-group', true );

    if( !empty( $feature_group ) ){
        $content .= esc_attr( $feature_groups[ $feature_group ] );
    }

    return $content;
}
add_filter( 'manage_edit-house_feature_sortable_columns', 'add_feature_group_column_sortable' );

function add_feature_group_column_sortable( $sortable ){
    $sortable[ 'feature_group' ] = 'feature_group';
    return $sortable;
}
?>

What am I doing wrong?