Why is my page not showing up on my published SimDif website?

Why doesn't this page show on the published site?

If you have tapped on the lock icon in the top-right corner of a page, this page won't show the next time you publish your website. Tap on that icon again to unhide the page.

Note: This feature is useful when you want to prepare a page in advance, like a draft for a big update on your website.