Thank you for reaching out to the API Support team here at Constant Contact. Is this a form you created from scratch?
If this is generated by a 3rd party app or integration, which one is it? Since 3rd-party integrations are not built or supported by Constant Contact directly, I'm limited in the scope in which I can help with any problems with it. Have you reached out to the integration developer for assistance? If so, what was their response?
Please let me know if you have any other questions!