I created a simple lightbox and added 20 or so images. If you view the live site you will see 2 grey boxes inserted which, when you click on them stalls the gallery and creates an everlasting spinning timer.
Those grey boxes are not in the lightbox. Looks like a bug to me.
Live site and page: http://www.tonymills.com/gallery.html (The lighbox is in the 2nd section down which is currently hidden.)
Shared site: https://preview.webflow.com/preview/tony-mills?preview=6bc04eef93d19fe27c0ee89b6197ba59