wp_nav_menu – not working with # and ? in URL

The theme of my website inserts a navigation bar on the left-hand side of each page – the code to accomplish this is at the end of this message. This works great – except when a URL is extended with a hash or question mark (pagename/#foo or pagename/?foo).

I’ve done some experimenting to see when it will work and not work:

1. Works – A hyperlink contains pagename/#foo. When this hyperlink is clicked, the page is loaded with a URL of pagename/#foo and the navigation bar appears.
2. Does not Work – A page is loaded by typing pagename/#foo as the URL. The navigation bar is gone.
3. Does not Work – A page is reloaded with pagename/#foo as the URL. The navigation bar is gone.
4. Does not Work – A page is loaded by typing pagename/?foo, reloaded with a URL of pagename/?foo, or loaded from a hyperlink on another page linking to pagename/?foo.

I’m very new to WordPress – this website was not designed by me, but I will be charged with maintaining and adding to it, so I’m here to learn. Much thanks in advance to anyone who can help.

Page Template

<div id="left_col">
<?php get_sidebar('medical'); ?>
</div>

Page Template Calls This

<?php
// use wp_list_pages to display parent and all child pages all generations (a tree with parent)
wp_nav_menu( array( 'theme_location' => 'medical', 'sort_column' => 'menu_order', 'container_id' => 'left_nav') );
?>