Wrap-up code returns null in analytics detail query?

NICE CXone API & Integrations
1

I’m pulling interaction details for our WFM adherence reports using the Analytics API. The query runs fine, but the wrapUpCode field is always null, even though agents clearly selected codes. Here’s the JSON payload I’m sending:

{
 "groupBy": [],
 "metricTypes": ["detail"],
 "filter": {
 "type": "interaction",
 "filterType": "detail",
 "operator": "equals",
 "value": "voice"
 }
}

Is this a known limitation or am I missing a parameter?