You mentioned that you use Edge due to it being like IE, which is what you are used to. Is there a reason why you aren't using IE? It's still usable in Windows 10, and although they aren't going to be releasing any more versions of it, the present one (IE11) is still getting security updates.
Also, mentioned above, it would be a great idea to install Glasswire, which will tell you just what is using data on each Windows computer it's installed on. If you already have it installed from being talked about months ago, disregard this.
Lastly, you said that this problem recently crept it's ugly head again. Have you checked to make sure that your syncing and "updates from more than one place" haven't been on, or at least turned back on somehow. Both of those can use a LOT of data, especially the updates from more than one place if it's set to share with everyone on the net.
Lastly again, regarding Edge, it's still a "work in progress." I, personally, don't trust it. I use IE and Chrome, but Chrome more and more every day.