Analytics API returns null for 30-minute tHandle buckets

NICE CXone API & Integrations
1

I’m querying POST /api/v2/analytics/conversations/details/query to get agent utilization broken into 30-minute intervals. The response comes back with valid headers but the tHandle, tAcw, and tHold fields are null for every bucket. The filter payload is valid since it works for hourly intervals, so the issue seems specific to the 30-minute granularity. Here is the query definition:

{
 "dateFrom": "2023-10-01T00:00:00.000Z",
 "dateTo": "2023-10-01T23:59:59.999Z",
 "groupBy": ["agentId"],
 "interval": "PT30M",
 "metrics": ["tHandle", "tAcw", "tHold"]
}

Any idea why the metrics drop out at this interval?