Posts in Newspaper theme thumbnail does not load properly
how to fix it
have you set your images for all post? or just you have import demo and images are missing.
All page has feature image set which is post thumbnail show. set image for all post
Pages are not post/blog. You have to set images going through wp-admin => Posts and edit all posts and set your images (featured image). If you already did that then please contact Newspaper theme Author Support and let them know. Theme Author will be happy to assist you.