You created a blog page and selected desired parameters, like blog layout, categories to display, number of items on the page etc. But still after saving you see the blog in a list style with no changes.
Most likely you selected some page as the main blog page via Settings>Reading>Posts page field.
This parameter is the standard option for WordPress. If you are using one of the default WordPress themes, like Twenty Fifteen, you have to choose a blog page from the list. If you leave the field empty, your posts will only be accessible via other navigation features such as category, calendar, or archive links.
But if you are using any other WordPress theme, for example, a Crumina theme, this parameter will conflict with the themes settings. That’s why when you set up the blog page, its settings can be overridden by default WordPress settings.
In this case, you have to cancel selection via Settings>Reading>Posts page field.