Statistics API /api/v2/analytics/queues/realtime returns empty data for active queues

We are building a Terraform module that validates queue health metrics before applying configuration changes. The requirement is to fetch real-time observation data, specifically the number of waiting interactions and available agents, for a set of queues defined in our state file. We are using the Statistics API endpoint /api/v2/analytics/queues/realtime with the interval parameter set to PT0S to get current state.

The request is authenticated using a client_credentials token, which we have verified is valid by successfully calling /api/v2/users/me. However, the response payload consistently returns an empty data array, even though we know these queues have active traffic.

Here is the Python snippet we are using to make the request:

import requests
import json

def get_queue_metrics(queue_id, auth_token):
 url = f"https://api.mypurecloud.com/api/v2/analytics/queues/realtime"
 headers = {
 "Authorization": f"Bearer {auth_token}",
 "Content-Type": "application/json"
 }
 params = {
 "groupBy": "queue",
 "interval": "PT0S",
 "query": json.dumps({
 "predicates": [
 {
 "type": "in",
 "field": "queue.id",
 "values": [queue_id]
 }
 ]
 })
 }
 
 response = requests.get(url, headers=headers, params=params)
 return response.json()

# Usage
result = get_queue_metrics("abc-123-xyz", token)
print(result)

The response we receive looks like this:

{
 "totalCount": 0,
 "pageSize": 100,
 "page": 1,
 "data": []
}

We have tried adjusting the interval to PT1H but that only returns historical data, not the real-time snapshot we need for the validation logic. The documentation mentions that real-time data is available for queues, but we are not seeing any records. Is there a specific permission scope missing from our OAuth client, or is the query predicate format incorrect for the real-time endpoint? We have checked the analytics permissions in the Genesys Cloud admin console, and the service account has analytics:read enabled.