Trying to understand why my Data Action fails to map the external REST response. I am calling a secure endpoint using an OAuth bearer token retrieved via a previous action. The HTTP request returns 200 OK with a valid JSON payload containing data.customerId. My mapping logic uses assign result.customerId to response.data.customerId, but the action consistently returns a 400 error stating ‘Invalid JSON structure’. The raw response is clearly valid JSON. Why does the mapping engine reject this specific path?