You have a couple problems that are likely causing unpredictable results
For example, your using the variable name $post_object in both the parent and sub loops. wp_reset_postdata(); needs to be called at the end of your first if ($post_object) {. You’ve also got a couple of nested setup_postdata( $post ); calls that can cause unpredictable results that I explain here https://support.advancedcustomfields.com/forums/topic/nested-post-object-fields/#post-48227
