You only get a notification the first time a program is run. After that you can still see the program in Advanced Settings ~ Security Settings ~ File Rating ~ Unrecognised files. If you remove the program from there using ‘remove’ you will get alerts for the program again.
If you are getting no notifications for any isolated files you have probably clicked on 'don’t show these notification in future on a AV or isolation notification. You can turn these notifications on again using Advacned Settings ~ General Settings ~ User Interface ~ Show notifications