Internet being gobbled up by brand new Macbook

Hello all - I just purchased a 16 GB Memory 15" macbook air, and over the last two days it has gobbled up over 10 GB of my data plan. My main uses of my internet are meetings, a couple youtube videos for entertainment, but that's it. Normally, I only go about 1-2G a day, depending on my meeting load. I don't stream movies/music and I turn off automatic updates as a rule. I also don't use the cloud and backup to a local drive.

I've noticed other people have had this issue, and some said the dynamic screensavers being downloaded onto your laptop may be the issue, but I use my own pictures. I reviewed some of the older threads from earlier this year about this, turned off screensaver, turned off background refresh, but I don't have the coding background to start altering scripts in terminal.

Did Apple ever issue a bug fix for this or said anything about the problem? I keep getting brought back to this forum when searching for answers, so thought I'd see if there were updates.