Cox data usage discrepancies

Just as an aside, I have a network monitor on my router and it's really close to what cox is reporting.  I thought they were off too, until i put in the monitor and started noticing all the traffic that I didn't expect.  Most of it was from background updates to games or OS and continual streaming.  My mother had the same issue and she lived alone and didn't use internet that much (she thought).  It turns out she was using a fireTV stick that kept streaming after she turned off the TV.  She didn't realize that she was eating up her usage when the TV was off.  once she figured that out it was all sorted.