Why is my Apple ID still locked for security reasons

This is a user to user forum and Apple is not here. We have no way of knowing why it is still locked. See if this helps: If your Apple ID is locked or disabled - Apple Support

Do you have multiple mail clients (devices or computers) trying to access iCloud mail, and one of those possibly with an old password? Same for other network services associated with your Apple ID. Stale passwords can trigger this. So can somebody else poking at your Apple ID.

If you don’t have two-factor enabled, set up your trusted telephone numbers and probably also a recovery contact on your Apple ID, and then enable two-factor.