If you put the Header element back in for your posts.
Then add this PHP Snippet to your site, it will move the header element to where the featured image is normally displayed:
add_filter( 'generate_page_hero_location', function( $location ) {
if ( is_single() ) {
$location = 'generate_before_content';
}
return $location;
} );
How to add PHP:
https://docs.generatepress.com/article/adding-php/