Why is the user's password not being changed?

Question

Active Directory

Hello.
When you create a new user in a Windows Server 2003 Enterprise Edition SP2 domain with the default password 123456, the "Require password change at next logon" checkbox is checked. Everything worked well until Monday last week, all new users from different departments (OUs) calmly changed the standard password to their own. But the problem started that after the user enters the standard password 123456, then he enters his password 2 times, presses change password, but the system answers that you need to change the password before the first login and only the "OK" button. As a result, it does not enter either with the password 123456 or with the one to which it was changed. If the password is set without the "Require password change at next logon" checkbox, the user logs in successfully.
1) GP which lies in the root of the domain with the name root Domain Policy has an item "Security Settings" where there are many account policies, I did not post screenshots. the last date of the change is in 2014, but if you need I can lay it out.
2) Time on the domain and workstations is the same.
Update 1.
Screenshot of the event log.

Answer 1

https://social.technet.microsoft.com/Forums/en-RU/...