Hello, I tested your website here and the highlighted items seems to be working fine when you scroll down, the only problem was when you clicked in some of the items, to fix that please add the following css:
(css/custom.css)
@media (min-width: 992px) {
#header .header-nav-main nav > ul > li.open > a {
color: #777 !important;
}
html #header .header-nav-main nav > ul > li.open > a.active {
color: #2388ED !important;
}
}
In our tested with that css it works perfectly, but if the problem persists, please try to change the data-offset of the data-spy plugin and also make sure the IDs are set to the correct SECTION. My suggestion is to create a section for the contact us content area and avoid the use of “footer” ID for the scroll spy plugin.
ScrollSpy is a simple plugin that automatically update the navigation based on scroll position to indicate which link is currently active in the viewport.
<body class="one-page" data-spy="scroll" data-target=".header-nav-main nav" data-offset="150">
Best Regards,
Okler Themes