Featured Image showing in full blog posts on homepage

I’ve just migrated to WP (Pretty Young Thing theme) from Blogger and am trying to update my most recent posts by adding Featured Images. I’ve changed my homepage to show 2 full blog posts before doing the Grid with Featured Images. But the full blog posts show the featured image at the top of the post, but not when you click through to the post page. You can see it on my temporary homepage URL – https://69.195.124.106/~blossoq6/