Analytics API aggregation query failing with 400 on queue grouping

Trying to hit POST /api/v2/analytics/queues/summary with an aggregation query that groups by queue/name and mediaType. The payload is minimal:

{ "groupings": [{ "name": "queue/name" }, { "name": "mediaType" }] }

It keeps returning a 400 Bad Request saying groupings[0].name is invalid. The docs say queue/name should work, but I’m getting nowhere.