Speech and Text Analytics API: Getting full transcript via GET /api/v2/interaction/analytics/conversations returns empty text

Is there a specific way to pull the full voice-to-text transcript for a completed interaction using the Genesys Cloud Analytics API? We are trying to automate our QA process by fetching transcripts directly instead of relying on manual review in the UI.

I am calling GET /api/v2/interaction/analytics/conversations/{interactionId} with the correct headers and a valid bearer token. The request returns a 200 OK, but the text field in the response is always empty, even though I can see the full transcript in the Webex Contact Center admin console. The status shows as completed.

Here is the relevant part of the JSON payload I get back:

{
 "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
 "type": "voice",
 "status": "completed",
 "text": "",
 "transcriptionStatus": "completed"
}

I’ve checked the interaction ID and it matches. The transcript is definitely there in the UI. Am I hitting the wrong endpoint? Should I be using the Conversation API instead, or is there a delay in the Analytics API data population that I’m missing? We are on the US-East region if that matters.