Lead Developer
The “Post Image” is the feature image for blog posts excerpts. If you’ve added your page header to the post excerpt, it will affect it.
Not sure what you mean about overlapping? Nothing should overlap.. Can I get a link to see it in action?
On single posts/pages, the Page Header add-on will replace the featured image if it’s set.
Post image hide/show only works on post excerpts (not single post view).