The Group Policy setting "Network Security: Force logoff when logon hours expire" is found under Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options. What if you try and configure this setting and it isn't being applied?
You've probably configured this setting in a GPO linked to an OU and not the domain. Unfortunately this policy is one of several under Security Options that are only applied when the GPO is linked at the domain level, not to OUs. The other four Security Options policies that behave similarly are:
- Accounts: Administrator account status
- Accounts: Guest account status
- Accounts: Rename administrator account
- Accounts: Rename guest account