Active/Passive Computer Use

On a similar note ...

 

I have the timing set so that it is supposed to only monitor the time that he is active on his computer.   He notoriously leaves his computer running or goes off and does other things.

 

He just got home from school about 10 minutes ago and I just got a notification that he has reached his daily time limit.

 

I think that this setting isn't working correctly.  I've gone back to verify and I think I've got the settings correct, but if it is tracking time when he is off the computer or the computer is not in use, then this feature is much less useful for me.

 

Does this make sense and do we have any ideas on how I can correct?