Posts Page no longer displaying featured images etc.

The posts page of the website I’m working on (https://tategifford.com/updates) is not displaying featured images. The featured image still shows being set when editing each post. It just doesn’t show up with the post summary on the posts page. How do I get them to display?

Also, the menu/navbar is overlapping the top part all the pages other than the home page. It is like a sticky menu bar that continuously shows at the top. Where can I turn that off? I don’t see a setting for it anywhere. Or, if I leave it on, how can I push the rest of the page content down so that the menu doesn’t cover it up?

The page I need help with: [log in to see the link]