Unstable Ping on fast internet speed

I can download files off of internet at a stable 2mb/s and the upload is just as high but, when I play Overwatch my ping goes from 140 (140 is my average) to few hundreds more and back down again at a very unstable pace. And there are absolutely no background apps that could be using internet. The only thing open is the game with Blizzard app. Could the Blizzard app be downloading updates while I’m in game? I do have that option unticked… Please help! ;(

Are you using mobile broadband to connect?

Also, please include the requested WinMTR in your reply: