I wrote a PHP program that recursively retrieves all products in the catalog using the Stores > Catalog REST API. See process here: https://dev.wix.com/docs/rest/business-solutions/stores/catalog/filter-and-sort
Back in April it was returning all of the products. Now it is only returning 462 of the 29,000+ products in the catalog. Those 462 products are very old. I verified the wix_site_id and Authorization key. I use other REST APIs in my programs multiple times each week.
Is there a bug or a new version?