see here an example page ( only with a color-section on that page that represents the footer-page )

https://webers-web.info/navigation/

for that menu item in the main nav i gave a custom-class to that menu-item: pseudoburger and used the label :
<span class="av-hamburger custom-burger av-hamburger--spin"><span class="av-hamburger-box"><span class="av-hamburger-inner"></span></span></span> – this is exactly the usage of the enfold burger icon – plus a custom-class (custom-burger).

the color-section got the ID: pseudoburger. (#pseudoburger)
( or if you use the footer-page for that – then you had to adjust all to that ID : #footer-page )

i placed now a snipptet to my child-theme functions.php:

function a_pseudo_burger_menu(){
?>
<script type="text/javascript">
	(function($) {
		$('body').on('click', '.pseudoburger > a',  function() {
			$('#pseudoburger').toggleClass('visible-page');
			$('.custom-burger').toggleClass('is-active');
		});
	})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'a_pseudo_burger_menu');

and on quick css:

#top #pseudoburger {
  position: fixed;
  top: var(--enfold-header-height);
  left: 0;
  z-index: 50;
  height: 100%;
  opacity: 0;
  visibility: hidden;
  transition: opacity 1s ease;
}

#top #pseudoburger.visible-page {
  opacity: 1;
  visibility: visible;
  transition: opacity 1s ease;
}

#top .header_color .custom-burger.is-active .av-hamburger-inner, 
#top .header_color .custom-burger.is-active .av-hamburger-inner::before, 
#top .header_color .custom-burger.is-active .av-hamburger-inner::after {
  background-color: darkblue !important;
}

to get a “footer-page” with dynamically feed menues – you can use the menu shortcode :

function custom_named_menu_shortcode( $atts ) {
    extract( shortcode_atts( array(
        'name'  => '', // Default to an empty menu name
        'class' => 'custom-menu', // Default CSS class
        'depth' => 0, // Default depth (0 for unlimited)
        'title' => '', // New: Default to an empty title
        'title_tag' => 'h2', // New: Default title HTML tag
        'title_class' => 'menu-title', // New: Default title CSS class
    ), $atts ) );

    $output = ''; // Initialize output variable

    // If a title is provided, add it to the output
    if ( ! empty( $title ) ) {
        $output .= '<' . esc_attr( $title_tag ) . ' class="' . esc_attr( $title_class ) . '">' . esc_html( $title ) . '</' . esc_attr( $title_tag ) . '>';
    }

    if ( ! empty( $name ) ) {
        $output .= wp_nav_menu( array(
            'menu'            => $name,
            'menu_class'      => $class,
            'container'       => 'nav', // You can change this to 'div', false, etc.
            'container_class' => $class . '-container',
            'echo'            => false, // Important: returns the menu HTML instead of printing it
            'depth'           => $depth,
        ) );
    }
    return $output; // Return the accumulated output
}
add_shortcode( 'named_menu', 'custom_named_menu_shortcode' );

it is used like this:
[named_menu name="your-menu-name" class="my-custom-menu" depth="2" title="Our Main Menu"]

then you can setup your layout with codeblock elements – each of them represents a menu ( or different shortcode – f.e. social-media )

but for that i wouldn’t use the enfold burger icon – instead i would place a custom Button – perhaps a fixed button to toggle a class to hide/show this page.

Look to your example page of thedive.com – its footer is exactly the burger content ;)
so maybe styling a footer-page and redeclare the hamburger icon with a different event that brings that footer to fullscreen and to fixed position ( left: 0 ; top: var(–enfold-header-height) ) is a possible solution. ( no automatic menü – but that way you like to have it)

have you refreshed all cachings (maybe you got a caching/optimization plugin) – did you “Delete Old CSS And JS Files?” on Enfold – Performance?

Next Hint:
These settings are nearly the last that are loaded – even after quick css – so if you got a mistake on quick css ( missing closing brackets , komma instead of semicolon etc. they will be not loaded. So check your quick css.

If you got a link to that page – we can check what happens.