Main blog page shows full post instead of excerpt only for 1 blog post

Hi there I am currently working with a WordPress site that uses Shapely for it’s theme. The blog is setup to point to a static full width page that shows all blog posts published.

The reader settings are set to excerpt in WordPress and no external plugins are in place regarding post excerpts.

I have gone to publish a blog post however which is set to private and when I go to preview the blog page whilst logged into WordPress all posts show with no excerpt just title, image and read link however this one blog post shows a full preview of the entire content.

I originally fixed this by adding a featured image which was missing however the issue has started appearing again and I need to get it sorted before I can publish the post live.

Wondering if this is a known issue and there is a workaround I can apply.

Thank you