WordPress Menu Navigation links not working

Here are a couple things I noticed.

You don’t want to include the <a> inside of link_before or link_after, you will get 2 links if you do that. You also don’t need the <ul>. Instead I think you want something like this…

<?php
    wp_nav_menu(array(
        'theme_location' => 'primary',
        'before' => '<class="nav-item active">',      
        'menu_class' =>'navbar-nav mr-auto',
        'link_before' =>'<span class="nav-link">',      
        'link_after' =>'</span>', 
        'container' => false, 
        'items_wrap' => '%3$s'
    ));
?>

You should read more about wp_nav_menu.