Order the package by ID instead of only Title or Publish Date. Your shortcodes instructions say: order_by: field name to sort packages, you can sort by title, download_count, create_date, update_date or id , its a optional parameter, if you skip this parameter “id” will be taken as default.
I followed your instructions here: https://www.wpdownloadmanager.com/doc/short-codes/wpdm_category-query-all-downloads-from-one-or-more-categories/
How do I assign an ID to the package so that we can order by ID. THanks