Bootstrap Theme Migrated to WordPress

Question

Looking for your expertise, as I'm fairly new using WordPress and I'm in the process of migrating bootstrap theme into it.

Problem: I have a navigation menu in the header and want to have a dropdown menu in one of the buttons (Clients). Currently when I add a page called "Travel Insurance" it as a "Sub item" via Appearances -> Menu it pushes the "Clients" menu to the top and "Travel Insurance Waiver" shows up underneath not as a dropdown of Clients.

https://i.stack.imgur.com/Hwx5R.png https://i.stack.imgur.com/NSRaL.png https://i.stack.imgur.com/hJpeR.png

Code using dev tools

    <header class="site-navbar site-navbar-target" role="banner">

        <div class="container">
          <div class="row align-items-center position-relative">

            <div class="col-3 ">
              <div class="site-logo">
                <a href="index.html" class="font-weight-bold">
                  <img src= "" alt="Image" class="img-fluid">
                </a>
              </div>
            </div>

            <div class="col-9  text-right">

              <span class="d-inline-block d-lg-none"><a href="#" class="text-white site-menu-toggle js-menu-toggle py-5 text-white"><span class="icon-menu h3 text-white"></span></a></span>

              <nav class="site-navigation text-right ml-auto d-none d-lg-block" role="navigation">

                   <ul id="menu-main-menu" class="site-menu main-menu js-clone-nav ml-auto"><li id="menu-item-285" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-home menu-item-285"><a href="http://box5463.temp.domains/~daydreo9/">HOME</a></li>
<li id="menu-item-116" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-116"><a href="http://box5463.temp.domains/~daydreo9/about/">ABOUT</a></li>
<li id="menu-item-193" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-193"><a href="http://box5463.temp.domains/~daydreo9/escapes/">ESCAPES</a></li>
<li id="menu-item-237" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-237"><a href="http://box5463.temp.domains/~daydreo9/request-a-quote-2/">REQUEST A QUOTE</a></li>
<li id="menu-item-231" class="menu-item menu-item-type-post_type menu-item-object-page current-menu-item page_item page-item-229 current_page_item menu-item-has-children menu-item-231"><a href="http://box5463.temp.domains/~daydreo9/request-a-quote/" aria-current="page">CLIENTS</a>
<ul class="sub-menu">
    <li id="menu-item-377" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-377"><a href="http://box5463.temp.domains/~daydreo9/travel-insurance-waiver/">Travel Insurance Waiver</a></li>
</ul>
</li>
</ul>


              </nav>
            </div>


          </div>
        </div>

      </header>

Functions.php File

 add_theme_support('menus');

 register_nav_menus(
     array(

         'top-menu' => __('Top Menu','theme'),
     )
);

Header.php File

                    wp_nav_menu(

                        array(
                            'theme_location'=> 'top-menu',
                            'menu' => 'home-section',
                            'container'=> 'ul',
                             'menu_class' => 'site-menu main-menu js-clone-nav ml-auto',

                            )
                        );?>```