Unexplained large mobile data use while connected to Wi-Fi

Hi, y’all…

This happened last week.

I had used my brand-new iPad Air 7 to watch a livestream in the morning. The whole time it was plugged into power and on my home WiFi. (I screen mirrored it to my AppleTV to watch it.) The livestream ended about 11AM, and I put down my iPad.

I don’t know if these are salient facts, but I did not quit the app that had been doing the live stream, nor did I sleep my iPad. It was lying on the table, plugged into power, with the page from the by-now-ended livestream showing. (I didn’t think it would matter, except maybe get warm.) I then lay down for a short nap. I didn’t touch my iPad the whole time (I was asleep). I got out of bed about three hours later to discover that my iPad had sucked up a full gigabyte of mobile data, in the half-hour immediately before I ended my nap (which makes me wonder what might’ve happened if I had gotten up after two hours, say, instead of three). The only reason that it didn’t take more is because my data service limit is 2GB/month, and it had hit my limit.

I want to emphasize, I was on my home WiFi network. I can think of no reason why my iPad would’ve accessed mobile data at all. And even if it did, how could it suck up that much data that quickly? A full gigabyte in half an hour?

Something similar has happened in the past, although not for a long time, where for reasons I am unable to explain, I use up a whole bunch of mobile data in a short time.

Any thoughts? TIA.

Jeff 🤔😉😊