Hello @MikeTheBike,
Thanks for writing in!
Since you have installed a caching plugin WP Super Cache, please clear your plugin cache before testing your site. This can cause the changes to not take place on the front end. It will eventually show up when the cache regenerates, but it’s not ideal if you’re looking to see your changes immediately. Caching plugins are best to turn on only when you’ve finished building the site.
And then your blog index is displayed with the help of the grid plugin. Please make sure that you haven’t set 5 items for mobile in your grid settings. You may need to edit your grid and check the settings:

Hope this helps. Please let us know how it goes.