It was either this upgrade or the last one ( 20.8 ) that has introduced a new problem.
I have the Password Protection enabled and set but now I can no longer access anything unless I'm logged in as an administrator on the machine. If a non administrative user tries to access the UI or temporarily disable the shields... a dialog is shown with the message "You are not allowed to perform this action, please contact your system administrator.".
I cannot work with this.