This sounds like a really counterproductive system. Usually in age verification, you prove that you're over a certain age. 9 year olds don't have very many ways to prove that they're 9 years old. What's stopping the creeps from pretending to be younger than they are?
They automatically assign you to an age group based on AI/guessing/face verification. If you've been assigned to an incorrect group, you need to do KYC verification with ID.