old version items missing from Top Campaign Content

Hi,
we use Taboola Backstage API in our product, using this url "backstage/api/1.0/%s/reports/top-campaign-content/dimensions/item_breakdown?start_date=%s&end_date=%s", we see that there are items missing from the response, all items that are labeled "(old version)" that are present in the Taboola UI in Top Campaign Content are missing from the API response, I tried looking into the docs but couldn't find any clue related to (old version) items and how to pull them!!
any advise on why there are missing?