With a 4k desktop and a 1920hd game resolution, if you tab out of the game, and back into the game, the mouse cursor size is scaled from the proper 1920HD size that it starts with, to the smaller 4K screen mouse cursor. The 4k mouse cursor is then far too small to use in game.
This is the last remaining significant bug for me as a 4K monitor user.
I'm playing 4k too, and I completely agree with the cursor issue. What did u mean about the 1920HD size tho? As far as I'm aware, it's always been the small 4K size for me.
Also, here's a link for anyone wondering what the cursor looks like you play on 4K. Try spotting the spotting the cursor. (Keep in mind when you are actually playing, you have to know where it is at a glance because you're constantly looking around.) https://youtu.be/BQG92HATfvE?t=15m41s
