Scenario is playing a game, like DOTA2 on Steam, and I move the cursor to the bottom of the screen to scroll downwards, and then the window alt-tabs out to the desktop. If move the cursor up, I alt-tab back into the game.

I noticed that if I'm in the desktop, and I do the same thing where I move the cursor to the bottom of the screen, I lose focus on whatever window that has focus.

If I quit the DisplayFusion application, I do not experience this behaviour. I did just upgrade to the newest version... so I suspect that is the cause.

Any suggestions?

Actually nevermind, found the root cause.. had synergy running. dumb me