It can even occur when playing customs with friends - we can remake the game and without fail, the lag will be gone next game.
I am on 50 down 5 up low latency internet and a very stable rig which I use for streaming regularly. This happens both on and off stream so I know that's not the cause.
Given that it was flawless until HoTS release, and only occurs in specific games, for the duration of that entire game, this seems like something on blizzard's end, so here I am. Can a blue help me out on this one?