Data Action success output mapping to undefined despite valid JSON response

Architect keeps dropping the payload when mapping the success response. External endpoint returns a 200 with a flat JSON object, but the Data Action config pushes undefined into the flow. Got the JSON path set to $.result.token in the mapping block, yet the downstream action never sees it. Tokio’s polling the webhook fine, so the upstream side looks clean. Here’s the mapping config I’m passing to the Data Action definition:

{
 "successMapping": {
 "outputToken": "$.result.token"
 }
}

Path syntax looks correct. Just getting undefined back every time.