Data usage

I have seen on my iphone that norton has used all of my monthy data allowance. Why when I have been using WiFi 90% of the time?

What iPhone are you using and what iOS version? 

What version of Norton 360 iOS are you using?

Can you post a screenshot showing Norton using this data?   

Instructions to post screenshots can be found here
https://community.norton.com/forums/how-post-image-forums-0