Analytics API groupBy queue.id and media.type returns empty

Is it possible to group by both queue.id and media.type in a single aggregation query? I’m trying to build a report that breaks down conversation counts by queue and then by media type (voice vs chat) for a specific date range. I’m using the Python SDK to construct the query.

Here’s the payload I’m sending to POST /api/v2/analytics/conversations/details/query:

{
 "dateRange": {
 "startDate": "2023-10-01T00:00:00.000Z",
 "endDate": "2023-10-02T00:00:00.000Z"
 },
 "groupBy": ["queue.id", "media.type"],
 "aggregations": [
 {
 "type": "count"
 }
 ],
 "select": ["queue.id", "media.type"]
}

The API returns a 200 OK, but the results array is always empty. If I remove media.type from the groupBy and select arrays, I get data for the queues. Same if I only group by media.type. But combining them yields nothing. I’ve checked the event logs and there are definitely conversations for those queues in that timeframe. Is this a known limitation with multi-dimensional grouping in the details query endpoint? Or is the syntax for the groupBy array different than I think?