Analytics API: Getting 500 on agent utilization query with 30-min intervals

Pulling agent utilization metrics (tHandle, tAcw, tHold) using the Analytics API. I’m trying to get a breakdown by 30-minute intervals for the last 24 hours. The query works fine for hourly intervals, but switching the interval to 30 minutes triggers a 500 Internal Server Error. Here’s the request body I’m sending to POST /api/v2/analytics/agents/utilization/query:

{
 "dateFrom": "2023-10-27T00:00:00.000Z",
 "dateTo": "2023-10-28T00:00:00.000Z",
 "interval": "PT30M",
 "groupBy": [
 { "name": "agent", "type": "ENTITY" }
 ],
 "metrics": [
 "tHandle",
 "tAcw",
 "tHold"
 ]
}

I’ve checked the Event delivery logs and nothing shows up there, so it’s not a webhook issue. The payload validates against the schema, and I’m using a valid OAuth token with the analytics:read scope. Is there a known limit or bug with sub-hourly intervals for this specific endpoint? I can’t find any docs mentioning a restriction on PT30M.