Using the sandbox feature,under the web browser there is a maintenance tab to delete the contents from the sandbox. I noticed when I click this tab on, the only way it deletes the contents if I reboot my system, is this normal?? Or am I suppose to wait 4 or 5 minutes for the sandbox to be empty?? ??? I was under the impression when I click on this tab it should empty the sandbox immediately. Appreciate some insight from the members. 
It’s deleted immediately if there’s no running virtualized webbrowser at the moment. Otherwise, it’ll be deleted during next reboot.
Pk thanks for your help appreciate your assistance