High Cellular Data from Documents and Sync after iOS 13.1.3 and Catalina update

I've noticed over the last month that I have been using what I consider a ridiculous amount of data through system services, within Documents and Sync (1.2 GB in less than 4 weeks). Typically this number is less than 100 MB. The change seemed to happen when I upgraded to iOS 13.1.3, and also happened after I updated my MacBook Pro to Catalina. I have turned off cellular data for Files, turned off photo stream, Wifi assist is off, iCloud drive is off, and I'm not backing up my messages on iCloud either. I've looked up things from over a year ago, and the one thing I've seen is turning off 2-factor authentication, but after it stopped one hack on my account, I don't think I'm ready to do that.