Home internet data usage is way over actual Router tracked usage

My average internet usage has been 100-400ish gb per month.  In February it shot up to almost 2000 gb and now half way through March it is at 1000+ gb.

We have reviewed all of the devices listed on the Router and they are all known and seem to be working as expected.  Nothing rogue.

I turned on my 'Traffic meter' on my Cable modem/router to double check that how much is actually going through the devices in my house, and it is showing me using about 10-15gb per day.  Which matches expectations and is no where close to the 70-90 gb per day that would be needed to reach the terabytes being 'recorded' by Xfinitiy.

We had a technician come out and checked the lines and they said everything looks good and they don't know how to troubleshoot an issue like this.

they say everything looks good.  The network speeds are working 'as expected' and as they always have.  

Just the usage xfinity is recording/reporting we are using is WAY more than what we are actually using and what our cable modem/router is recording we are using.  

(p.s. your xfinity assistant is very unhelpful)