Videos don’t display in overview page for featured video posts and how to choose featured post

One of my preferred features of your theme was that videos, music and such would actually display up-front on posts that centered on those media. However, now I have the theme my blog displays the featured image (which I uploaded to use as the background for the title on the blog itself once opened) and not the video within the post as I hoped it would. Any ideas?

https://robmyles.co.uk/blog

It’s the first post.

I’d also like to know if you can feature posts full width that aren’t the most recent one?

Cheers

Rob