Enforce password History not remembering when resetting from Admin accounts.

Hi all,

We have a Windows AD Environment with multiple servers.  In those we have enabled the enforce password policy which defines the Enforce Password History = 3 for end users. But whenever user password are resetting from user side, it is working without an error. But when users try to reset their passwords contacting our help desk, usually the admins reset the users passwords. In that case we, when user password are reset from admin side, users can use the old passwords which saved in "Enforce Password History"

Any Idea Why..? I have re created the "Enforce Password History" policy but no luck..!