Good morning… last night before going to bed, I did a couple things but it looks like to solve this, relates to the need of an update to the theme. In a WordPress theme, there are two ways to add post content to a blog (which also relates to how it gets added to a full view of the post) like this:
the_content()
…and
the_excerpt()
The_content option is the most common which is what the default theme of WordPress is using, but what appears to be the more flexible is the_excerpt one. I will have to change this and also add another theme file. Long story short, by adding the_excerpt in the theme file, you can have the featured image show, but if you have that same image again or a different image in the first part of your post, the featured one will disappear when viewing the full post but then your inserted image will show instead.
So I will need to make this change and update today. If you don’t hear from me in the next 4 hours or so, follow up with me.