Header not consistent on all pages

Hey guys, great work on this theme. I’m loving the great default look and the high degree of customizability.

So, here’s my issue, though. Have a look at https://www.natashashannonjazz.com. I want the header on all pages and posts to be exactly the same as the ‘index’ page. Click on one of the pages on the nav bar, and you’ll see that this is not the case. I want the header to show either the default or the page’s featured image. See my other site https://www.steelpaladin.com for an example of this.

I’ve had a long, hard look at the CSS and PHP in this, and I’m frankly stumped. The only thing I’ve figured out when editing the CSS classes is that when I remove the .inner-page class from the body element, I get the desired result. But I have no idea what to change to make this stick without making the whole page disappear, nor can I fugure out exactly what attribute is being defined that is getting in my way.

Please let me know if you (someone) can help me out with this.

Thanks,