Apple won’t recognize my birthday—says my birthday doesn’t match info on file
Why won’t Apple recognize my birthday and why was my account locked for security reasons?
We are users like you, so we don't know why Apple won't recognize your birthday.
If your Apple ID is locked or disabled - Apple Support.
If you have changed your ID or password, have you followed the steps in this article?
What to do after you change your Apple ID or password - Apple Support.
If necessary, contact Apple ID Support. Based on multiple posts I have read, they may not be willing to help. See the Apple Support articles below for contact information.
Apple ID - Official Apple Support.
Contact Apple for help with Apple ID account security - Apple Support. (Link doesn’t always load)
Get Support Work through the screens to get a chat option.
Apple Support schedule phone call
https://twitter.com/AppleSupport. People have posted it may take an hour or more to get a response.
From the Apple Support article below.
Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.