Post grid shows all posts even though I selected one category

Greetings,

I\'ve had this work in the past, but now something seems to be wrong? When I create the post grid, I go to Query Posts > Post Taxonomies & terms > categories > choose the category of posts I want to show > update, but the shortcode stubbornly shows all posts in all categories, on the front end of the site.

Any ideas? Am I using the wrong setting to limit which categories show in the grid?

Thank you!