I have a custom post type with page-attributes declared so I am able to put in a menu_order number/field for sorting them via menu order. This all works as expected except this next issue.

I reset all the custom post type menu_order fields to 0 (int) with sql. I then refresh the site. WordPress then auto-increments menu order instead of leaving them all at 0. Does anyone know why this behaviour would happen?

Here is the sql for resetting all menu_order items to 0.

UPDATE wp_posts SET menu_order=0 WHERE post_type="custom_post_type"

Any help would be appreciated.