PATCH conversations/voice/{id} transfer to queue returns 400

Trying to transfer an active voice interaction to a specific queue via the Conversations API. Sending a PATCH request to /api/v2/conversations/voice/{id} with the JSON body below, but I keep getting a 400 Bad Request. The docs say toType should be queue but it’s not working.

{
 "to": {
 "id": "queue-uuid-here",
 "type": "queue"
 }
}

Any idea what I’m missing?