Yea it's the game. Countless people and my self still have this issue. It appeared after a patch from 2016, and Blizzard still completely ignores it telling it's the video cards drivers which now 2 years later is utter BS.
The only "fix" is to turn all details to low, then it seems like it won't happen.
If your screen is turning black with those black spots coming onto the screen, you can "counter" the problem by quickly moving your aim/view in the opposite direction where the black spots are appearing.
If yout screen has already gone black, the only fix I found that works for me is to go into video settings, change my screen resolution to another and then change it back again, and then there will be a fine picture again.
If you screen goes red, blue or green, then switching between screen ratio e.g from 16:9 to 16:10 to 16:9, can resolve the issue in game.
It happens to me on 3 different systems with GT 1030, GTX 1070Ti and GTX 1080.