I am working on Google Ads API. My goal is to find detailed information on the cost, clicks, etc. for each “Performance Max” campaign. When I use the following query:

SELECT
  campaign.id,
  campaign.name,
  segments.ad_network_type,
  segments.advertising_channel_type
FROM
  campaign
WHERE
  segments.date DURING LAST_30_DAYS
  AND segments.advertising_channel_type = 'Performance Max'

I see that the ad_network_type field has a value of ‘mixed’. I want to find detailed information on what constitutes this ‘mixed’ value (e.g., how many clicks, impressions, cost) for the components such as:

CONTENT 
GOOGLE_TV 
SEARCH 
SEARCH_PARTNERS 
UNKNOWN 
UNSPECIFIED
YOUTUBE

I found information in the documentation that such data can be retrieved from the detail_placement_view table:
https://developers.google.com/google-ads/api/fields/v15/detail_placement_view
https://developers.google.com/google-ads/api/fields/v15/detail_placement_view_query_builder
However, when I try to retrieve any data from this table, even with the simplest query, I always get an empty array as a result, for example:

I have tried this query:

SELECT detail_placement_view.placement_type 
FROM detail_placement_view 
WHERE segments.date BETWEEN '2024-01-01' AND '2024-05-26'

and it always returns me an emtpy array. I have tried manipulating this query, extracting different fields, increasing the date range, etc., but I always get an empty array. Why is this happening? Is this table still provided by Google, or is it deprecated? Does anyone have any information on this?