Kids can turn Norton on/off with toggle in settings

I noticed today that my son had been on his tablet way longer than the 1 hour time limit I had given him. So started looking around in his tablet and in settings there is a toggle on/off switch for Norton Family. He can turn it on or off with no password and I get no notification. What the heck!?! Same with my daughters tablet. They both have Nextbook tablets that are android devices. The software does me no good if they can just turn it on and off. Help please!