If you set a cookie and it does not appear to be working, it is likely due to the computer does not have the right permission or set as guest user.
To allow cookies to work, you need to temporarily grant admin privileges to the user account on the machine. Follow the steps here to use cookie based blocking https://support.timewellscheduled.com/article/setting-up-access-restrictions/). This will create a permanent cookie on the user profile and browser (repeat this if multiple browsers are to be used). Once the cookie has been set, you can then change back your user to the normal (non-admin) setting.
NOTE – If you can, we strongly recommend IP based blocking as it requires no special setup per machine and all machines in the network can be used without any setup.