Help with query by post category

To display life posts by category on a one page website (including the commentary form), I use this shortcode:
[qw_query slug="band"][wpsites_comments_template]

It should work with permalinks set to: …/%category%/%postname%/

The resulting page shows all posts not just those by selected category.

Any takers on what I a missing out on is greatly appreciated.

Thank you Jonathan for your promising plugin,

Mark