Stop old-dated posts from appearing up front

I’m moving a web site that was built in 2019. It has a lot of posts and pages. I am converting some pages to posts, and I’m giving these posts the publication date and time of the original page, i.e., in 2019.

Nonetheless, the posts are showing up on the front of the web site as if they are new. I’m also using Real Custom Post Order, but it is almost impossible and very hard work, to move a post from 2019 off the front of the site, back to where it belongs, in among the 2019 posts.

Have you any tips on how to do this easily?

Thanks for your time.

The page I need help with: [log in to see the link]