The header shows up but it has a transparent background, so that’s why you can’t see it until you sroll (then it turns black). The reason the header is transparent is because it’s designed to do that on the Homepage in order to display the background. The issue is that the 2nd page keeps the home
and front-page
CSS classes in the body/code, so it still treats the Header as if it’s being viewed as the homepage rather than a regular page.
Here’s a workaround –
This should add the black background for the 2nd page but will keep the homepage as it is –
.paged.featured-section .site-header {
background-color: #000;
}
Next add this to enable the space (margin-top) back for the .site-inner so it will appear as your regular pages –
.paged.front-page .site-container .site-inner {
margin-top: 100px;
overflow: hidden;
}
That fixed it when I tested it on your site. Let me know if that works.