On Wi-Fi Messenger just used 2GB of mobile Data

[mstrblueskys]

I have an HTC 10 that has been on WiFi all weekend. We got a mobile data warning, so I went in to check to see what I have been using and was blown away at Messenger's mobile data usage. I'll include the screenshots.

Is anyone else having this issue or is there any way to solve it aside from turning off mobile data for the app? It was still CRANKING away at the data when I took this screenshot, so it's off now.

Thanks for the help!