Hi Sonja
Its actually quite easy. First build your page then create a post with a 301 redirect to your page. On the post insert a line or 2 for your excerpt to show and don’t forget to put the featured image in.
I use the yoast seo plugin which gives the option for the 301 redirect.
Had the same problem and it was one of my plugins that was causing it. De-activated that plugin and it works like normal.