In Chosen, the first post on the blog will be displayed extra-wide filling both columns of content. This is true with additional layouts in Chosen Pro as well.
If you'd like to display the first post on the blog normally, follow these steps:
- Visit the Customizer (Appearance → Customize)
- Click on the Additional Options section
- Under the Make first post on blog extra wide? setting, select the No option
- Click the Save & Publish button at the top of the screen
