Active state on Anchor link appears too early on page/scroll?

I have an existing site created a while back in Adobe Muse, which includes a sticky sub-menu with anchor links to the sections below. In the Muse version, the “Active” state of the button only displays once the section is right at the top (around 100px from the top to be precise).

Muse: http://www.everydayconferencing.co.uk/auditorium-ground-floor.html

But in Webflow, I am unable to achieve the same result, with the “Active” state appearing half way down the page as I scroll. Put another way, the active state does not reflect the section currently in the top half of the page.

Webflow: http://everyday-conferencing-378f38c04cd65fbf3.webflow.io/kingston/auditorium-ground-floor

Any idea what I could be doing wrong?

Thanks.


Here is my site Read-Only: LINK
(how to share your site Read-Only link)