According to this doc we can use this endpoint (https://uccx-server/adminapi/campaign/{id}/contacts) to visualize Pending Contacts for a Campaign.
Strangely enough, this API returns empty data if the campaign is available. After some operations (e.g., reclassification of contacts), some data (not all) are returned. Moreover, if I disable the campaign, data are correctly returned.
Doc does not report anything about this strange behavior. Can somebody explain what is the rationale behind this output? I'm using a direct preview campaign but i believe this is not the reason of this issue.