Hi
I am not sure what the problem is, but on your site WordPress does not know what the page (and slug) for the Posts
post type archives is.
For example, if I had a custom post type called Houses
I might set WordPress up so that www.mysite.com/houses/
is the archives page that CPT. By default WordPress puts blog posts on the front page and so no archives page is possible, but you have set it to a static front page, but not set the blog page as the one that contains the posts. This may be because you are adding the posts to the page using some form of custom grid builder.
As it stands, you cannot use the Post Type display method, but you should use the As an archive method. The problem with this is that you then have to find the correct theme template to use.