Web filtering on Android only working very intermitently

Hi! I have recently installed Norton Family on my Android (Moto X 2014 running lolipop 5.0) and it's a great concept, but the web filtering is working very poorly. I have it set to block to adult content. When the phone is child mode, it seems to properly identify and filter adult sites about 1/5th of the time. And it seems to work in bursts, meaning when it is working it will work consistently for at least several attempts. Then a few hours later later it will not work at all and will not work consistently for several attempts. Then a few hours later I will try again and it might work again. 

2 things to note: 

1) I have never seen it go from either working to not working within one of these "bursts"....it only switches from working to not working after not being tried for a while. And most times, it does not work. 

2) Between these bursts, I am not changing any settings, and have been connected to the same wifi network the whole time. 

3) I am testing the filtering by attempting to visit the same adult site every time, so that is not the relevant variable. 

Please help! I desperately want to be able to filter adult content as this product advertises, but I need it to work consistently. Is there anything that can be done? 

Thank you,

-Ben