So I want to add a category bar on top of my webiste below the breadcrumbs, I added the below code to virtual header.php

<div id="munchycat" class="col12">
<li class="page_item">"
<?php wp_list_pages('depth=1&title_li='); ?>
<?php wp_list_categories('title_li='); ?>
</div>

problem - title_li=' which ensures that the word Categories is not displayed before the list is not working?

it looks like parameters passed to wp_list_categories are not working, anybody got a fix?

looks like you are right it doesn't pass the parameter. You might think about donating to FLYNN the theme developer to encourage him to keep developing Montezuma