A Smartcard provider is showing on the login screen and interfering with normal SP WLM login.

You see the Smartcard option on the sign on screen and need to disable it.

To disable a smart card provider in Windows, you can follow these steps:

Edit the registry: Open the registry key

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\Credential Providers\{8FD7E19C-3BF7-489B-A72C-846AB3678C96} and add a DWORD value "Disabled"=dword:00000001.

Should look like this:

Use Group Policy: Open the local Group Policy editor and navigate to Computer Configuration → Administrative Templates → System → Logon. Find the policy "Exclude credential providers" and configure it.

Disable Smart Card Plug and Play service: This removes the option to insert a smart card when logging in.

One or more of the 3 options above should work in most cases.