Add Listing page for new CPT

I am trying to add a new “Add Listing” page for my CPT. I got it to work, but I don’t quite understand why it works.

I created a new WP page “Add Supervisor Listing” with the shortcodes from the default “Add Listing” page. I modified the shortcode to add my post type, e.g., [add_listing listing_type=”gd_supervisor”]. When I attempt to preview the page it redirects to the add listing page for gd_places. The url uses my page but displays the gd_place listing contents. If I use a url like “/add-supervisor-listing/?listing_type=gd_supervisor” that includes the listing_type then it works. It seems that adding the listing_type to the shortcode doesn’t actually do anything.

Also, I have seen support postings saying to use “post_type=” and others saying type “listing_type=”. Which is correct? Is there V1-like documentation for the V2 shortcodes?