Biometric Appointment for Dependent child

[contactanant]

Hi All

For my Tier 1 extension, I received Biometrics appointment letter, we went to the post office to give Biometrics but for my kid they said it can not be done in the post office because the letter said no responsible adult found. I have given my biometric but it could not be done for my child.

Now I am booking an appointment for biometric application for Child and will also call them tomorrow.

Appreciate if someone can answer following questions:
1. I am choosing Tier 1 PBS dependent in the drop down and putting case Id and DOB accordingly but system says unable to find the applicant. I am guessing this could be related to above problem "No responsible adult found".
2. Is that a problem that main applicants biometrics were taken before dependent's?

Thanks for any response.