If you click through to request your offline data it appears that their regex to validate DOB is faulty and it fails the identity check requiring you to have to start a letter campaign to maybe get access to the data they hold about you.
(0[1-9]|1[0-2])/(0[1-9]|1d|2d|3[01])/(19|20)\d{2}
If the day you were born is between 10-29 it will not validate as a proper day.