Norton shows time spent on Android device while device known to be off!

Honestly, at this point I am really discouraged with Norton Family for Android devices. We have a hard enough time parenting without having false information from Norton!

The latest is that my son has been without his android device for 2 weeks. Last week shows no use. Today, I got a notification that my son's attempt to access a website had been blocked (exact time of attempt not shown in notification). Curious, given that both his devices (android phone and PC) were here while he was at school, I logged into Norton Family.

NF shows that he used the phone both Friday and Saturday, despite the phone's having been in our possession and securely locked. Meanwhile, there is no use shown for his PC (although he used his PC in front of me and obviously should have use shown). 

We have updated everything. Both devices are associated properly with his account. If Norton can't promise better reliability with this software, we are ready to cancel; it is actually causing fights because my son protests his innocence and -- seeing these false reports -- I wonder whether or not he actually was telling the truth now!