Genesys Cloud Analytics API: Getting 30-min interval breakdown for tHandle/tAcw/tHold

I’m trying to pull agent utilization metrics (tHandle, tAcw, tHold) broken down by 30-minute intervals using the Analytics API. The goal is to feed this into our OpenTelemetry pipeline for distributed tracing of high-latency interactions.

I’m using the GET /api/v2/analytics/conversations/summary endpoint with the following query parameters:

startTime: 2023-10-25T08:00:00.000Z
endTime: 2023-10-25T17:00:00.000Z
groupBy: interval
intervalSize: 30m
metrics: tHandle,tAcw,tHold

The API returns a 200 OK, but the response only contains a single bucket for the entire day, not the 30-minute slices I requested. The groupBy field in the response is empty or defaults to total.

{
 "data": [
 {
 "interval": "2023-10-25T08:00:00.000Z/2023-10-25T17:00:00.000Z",
 "tHandle": 12345,
 "tAcw": 5678,
 "tHold": 234
 }
 ]
}

I’ve checked the docs and intervalSize: 30m should be valid. Is there a different endpoint for time-series breakdowns, or am I missing a header? The groupBy: interval seems to be ignored when combined with these specific metrics.