Unable to Set/Change Pin for Windows Hello for Business
make a copy of the following folder:
C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\Ngc
Then delete the contents of that folder
Open settings and try setting a pin now
Set Registry Key
Set the following key to enable pin sign-in if it isn’t enabled
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\System\AllowDomainPINLogon
Source
https://superuser.com/questions/1279400/unable-to-set-or-remove-a-login-pin-on-windows-10