Personal Code Rejection After XML Gateway Acceptance

We are currently submitting company incorporation filings via the XML Gateway, and in a recent submission the XML request was accepted successfully by the Gateway without any validation errors; however, when we later checked the submission status, the filing was rejected with a message stating that the personal code is incorrect. Could you please clarify why the request is initially accepted by the XML Gateway if the personal code is invalid, and at what stage the personal code validation is actually performed during the incorporation process?