Hi Josh,
There is the possibility that the Form was originally saved as a Lead then later changed to Contact. Please try to "Clone" the Form and save the Clone to create new visitor as a Contact. If this does not work please try rebuilding the Form, making sure to choose "Contact" before saving the first time. If you still see this behavior after trying these two troubleshooting methods, please login in and open a support ticket here.
As long as they only renamed the Contact entity to Individual and it is not a brand new custom entity it should not affect the creation of a new visitor.