The "Sign-in Options" link is suddenly missing from my Windows 10 login screen. I had it defaulted to sign-in with PIN. Now it has reverted to signing in with a password without the option to change back to PIN.
Under Settings, Accounts -> Sign-in options, I now see the option to "Add" a PIN [instead of "Change" and "I forgot my PIN"], as if I had never set a PIN. If I click on "Add", I am allowed to add a PIN after entering my password. However, it appears the PIN is immediately forgotten by Windows because even after I've finished, it still shows only "Add" under the PIN section of Accounts -> Sign-in options. And if I logout, the login screen is still without "Sign-in options" under my name.
Running sfc /scannow showed no integrity violations found.
The last changes I had made to the OS were disabling some non-essential Services... I don't think that could be related to this issue, but let me know if there is a Windows Service on which the "Sign-in Options" depends.
Otherwise, let me know of any other way I might fix this. I liked the ability to sign-in with a PIN.