Win10 PIN code login can not be used normally

The PIN password is a new login authentication method added to Windows from Win8. It is also a login method that Microsoft highly recommends. During the installation of Win10, Microsoft will prompt the user that the traditional password is out of date. It is recommended to log in with a simpler but more secure PIN code.
If your device supports Windows Hello (Iris Scan or Fingerprint Scan), you will need to set a PIN to log in before using these features.
Some users may encounter the problem that the PIN code is not available during use. This is generally because the IPsec Policy Agent service is not enabled. In this case, you only need to set the service to start automatically, and manually restart it to restore normal. The detailed operation process is as follows:
• Enter “service” in the search bar search box, open “service"service”;

• find IPsec Policy Agent in the service Double-click to open its properties.

• Set the service startup type to “auto", click “OK>Save settings.
• Finally, manually open the service.

If you haven't used your PIN yet, try it out.