I have 3 blog posts published, but only one is showing on the home page. I have the # set to 10 in the “reading’ settings of WordPress. The one that IS showing on the home page is NOT showing up under myurl/blog page, however.
Please, go to the options Appearance->Customize->Static Front Page and set posts page as your “Blog” page. Now, only this page will response as blog page and all of the created posts will be displayed here.
WordPress allows only one page to choose as blog page. It is not possible to display posts on both home and blog page so, we suggest you to remove the blog page and make “Home” page as both front page and posts page. As only one page can be selected as posts page to display the post.