Sticky Submenu with underlined active item

Thank you for getting back to me this fast… :-)
I want the Sticky Submenu to underline the active menu item.
I have added this PHP Snippet:
————————————————————————
// Highlight one page nav

function activateMenuItem(){
?>
<script>
jQuery(document).scroll(function() {
var sections = jQuery(‘.iconbox’),
menu = jQuery(‘.av-submenu-container’),
nav_height = menu.outerHeight();
jQuery(window).on(‘scroll’, function() {
var cur_pos = jQuery(this).scrollTop();
sections.each(function() {
var top = jQuery(this).offset().top – 300,
bottom = top + jQuery(this).outerHeight();
if (cur_pos >= top && cur_pos <= bottom) {
menu.find(‘li’).removeClass(‘active-menu-item’);
menu.find(‘a[href=”#’ + jQuery(this).attr(‘id’) + ‘”]’).parent(‘li’).addClass(‘active-menu-item’);
}
});
});
});

</script>
<?php
}
add_action(‘wp_head’, ‘activateMenuItem’);
————————————————————————
And this CSS:
#top .av-submenu-container .active-menu-item,
#top .av-submenu-container .active-menu-item a {
text-decoration: underline !important;
}

But still no underlined active item.
The menu items are set as “Button Style (Colored)” and I did try the “Default Style” in case the problem lays here. But nope…

Thank you Ismael.
The links just leads to more confusion but I did try and follow the conclusions there.
Status now is that, since I don’t have a Child Theme, I put the following code in the functions.php using the plugin “Code Snippets”. The plugin works with other issues regarding the functions.php file, so I would expect it to work fine also in this case.
————————————————————————————
// a custom script
// add current-menu-item class to active item
function ava_custom_script_mod() {
if ( wp_script_is( ‘avia-default’, ‘registered’ ) ) {
wp_add_inline_script( ‘avia-default’, ‘
(function($) {
$(document).ready(function() {
const setActive = (entry) => {
let item = $(#top .av-subnav-menu a[href*=\'+ entry + \']);

if(!item.attr(“href”).includes(entry)) return;

let list = item.parent(“li”);
let parent = list.parent(“#menu-sub-menu”);

if(list.is(“.current-menu-item”)) return;

parent.find(“li”).removeClass(“current-menu-item”);
list.addClass(“current-menu-item”);
}

const createObserver = (entry) => {
let el = document.querySelector(entry);

const observer = new IntersectionObserver(function(entries) {
if(entries[0].isIntersecting === true) {
setActive(entry);
}

}, { root: null, threshold: [0.1] });

observer.observe(el);
}

const anchors = [“#dagsprogram”, “#grad”, “#praktisk”, “#indkvartering”, “#prisinformation”];

anchors.map(anchor => {
createObserver(anchor);
});
});
})(jQuery);
‘);
}
}
add_action( ‘wp_enqueue_scripts’, ‘ava_custom_script_mod’, 9999);
———————————————————————————————-

In Quick CSS I put this:
#top .av-subnav-menu > li.current-menu-item a {
color: red !important;
text-decoration: underline !important;
}
———————————————————————————————-
The “Full Width Sub Menu” does not go in a Color Section. So let’s not go down that road…

In the Full Width Sub Menu I did not add anything under Developer Settings.

The goal is simple: I want the active item to be underlined with a white line in the Sticky Submenu.

Please login and have a look. And advice what to do next. What am I missing here?

Thank you for a great support.

Wow, thank you very much – you’re the man! :-)
Did you notice that the wrong anchor link is sometimes underlined/highlighted in the sticky submenu? Maybe it has something to do with the fact that two anchor elements are visible at the same time and the sticky submenu is confused on which link to underline…?
Or should I place the anchors differently maybe?

You are correct – the problem is NOT there if I make the browser window a lot smaller.
Is there not a work around this issue? I can’t really just add more content to the anchor sections – just for the purpose of making the link underline work correctly.
Crossing my fingers :-) And thank you again for helping out here…

Unfortunately, it makes no difference… And I did try with many other values but no luck…
Any other ideas?
I would really love for this feature to work smoothly.

Thank you – it’s all working just fine now that I have put some more content around the anchor elements.
You can close this thread now.
Great support :-)