GetExternalContactAction returning empty contact object

Trying to wire up a GetExternalContactAction in Architect to pull customer data based on the inbound phone number. The data action is configured to hit our internal API, but the contact object coming back to the flow is always empty.

Here’s the payload structure we’re sending:

{
 "phoneNumber": "{{trigger.phoneNumber}}"
}

The API logs show a 200 OK with the correct JSON response, including name and email. Debugging the flow shows the data action succeeds, but the resulting contact fields are null. I’ve checked the field mapping in the data action settings, and everything looks aligned.

Is there a specific schema requirement for the response payload that GetExternalContactAction expects? Or is this a known issue with how Architect parses the external response?

Checked the event logs, no errors there either.