Guess Device is not pausing according to the set time consistently.

I am trying to setup parent control to allow my kids time to play, time to sleep and time to do home work.  However, xFinity is not only not helping but you are creating more problem for us.  I can't used the parent control section to set schedule for when each device should be on/off.  I have to use the guess device feature.  Guess device work great; however, it doesn't work consistently.  Sometime, I see that my kid computer has been paused but the internet is still active when I tried to browse the internet.  I checked the computer's name, I check the IP address, everything is consistent with the setting and schedule.  However, most nights it works and some night it just not working, I have to go in and manually unpause and re-apply the schedules.  This is frustrating.  If you make a software that work in such an inconsistently manner, why don't you just keep it to yourself so I can save my time and headache.  It's disappointing such a feature is lacking from such a big service provider.  Also, I wasted almost an hour each time I have to troubleshoot the pause feature of my guess device b/c your router admin page is slow as dog.  So is your website!  If I have a choice in my town, if you haven't monopolized the entire area, I would rather pay more to get a better service.