Random Alt Tabs in Game

I've been having an issue lately where mid game, I will just get alt tabbed back to my desktop. I have closed out everything in an attempt to stay in game as it's very annoying and can be prone to throwing whole fights for me but it doesn't help. :/ it doesn't do it every game but it happens often enough to be frustrating and a nuisance. Relogging doesn't appare to help either.