When WordPress is not fresh install, demo posts not going to import during one click theme setup.
To import demo posts manually
#1. Admin > Tools > Import > WordPress > Install Now

#2. Unzip Theme Files
Theme Files include demo posts and widgets files that can be found under “demo” folder.
#3. Run Importer
Import coachingplus-posts.xml/recipeblogger-posts.xml/cuisinerecipetheme-posts.xml depends on theme you installed.

#4. Upload file and import

- Assign Author to existing author or import author
- Import Attachments so all posts images also get imported. check “Download and import file attachments“
- Submit
After import, screen will show “All done” message

NOTE: Sometime Featured images not set on import because its how wordpress import work so that may be you need to set manually otherwise import works great.