Hi!
For the the parameter “cat” in order to work you must pass the category ID. For example cat=6
Not the category name or the category slug.
About the short description of each post by default is used a truncated version of the content but if your are using shortcodes or iframes in this text you can use the excerpt instead. You can use the excerpt with this parameter : descr_excerpt=”true”.
Also the length of this description can be changed with the parameter “descr_length” (default:15 words)
For a complete list of the specs for the shortcodes of the theme visit: https://pokatheme.com/documentation-poka-theme-v2/#sect5