Unable to POST Contact using email

I’m currently trying to POST a Contact with just an email, and am currently being met with a 400 error:

Request body:

{"name": "Kim Chuc", "email": "email@gmail.com"}

Response body:

{
    "type": "error.list",
    "request_id": "0004n8c4t4e6a3olv82g",
    "errors": [
        {
            "code": "invalid_document",
            "message": "either_email_or_user_id_present validation failed"
        }
    ]
}

Based on the docs, email is the only required field to POST a Contact and I’ve double checked to make sure the email doesn’t already exist:

Has anyone ever come across this issue before?