Empty item id and name in "Top Campaign Content Report"

Sometimes the Top Campaign Content Report (https://backstage.taboola.com/backstage/api/1.0/{account_id}/reports/top-campaign-content/dimensions/item_breakdown) contains results without ad name or id. E.g.

{
  "item": null,
  "ad_name": null,
  "custom_id": null,
  "item_name": "xxx",
  "description": null,
  "thumbnail_url": "xxx",
  "url": "xxx",
  "campaign": "xxx",
  "campaign_name": "xxx",
  "content_provider": "xxx",
  "content_provider_name": "xxx",
  "content_provider_id_name": "xxx",
  "impressions": 20494,
  "visible_impressions": 9111,
  "ctr": 0.34,
  "vctr": 0.76,
  "clicks": 69,
  "cpc": 0.342,
  "cvr": 2.9,
  "cvr_clicks": 2.9,
  "cvr_views": 0,
  "cpa": 11.79,
  "cpa_clicks": 11.79,
  "cpa_views": 0,
  "actions": 2,
  "actions_num_from_clicks": 2,
  "actions_num_from_views": 0,
  "cpm": 1.15,
  "vcpm": 2.59,
  "spent": 23.58,
  "conversions_value": 0,
  "roas": 0,
  "currency": "EUR",
  "create_time": "2025-07-18 14:36:41.0",
  "old_item_version_id": "xxx",
  "learning_display_status": "LEARNING"
}

We've requested data from 2 days ago. Can someone explain me why and how long it will take (if ever) until the report is stable?