Same issue.
Dual-screen setup.

- Keyboard suddenly stops responding in game.
- Keyboard continues to function outside of game in other window.
- Mouse suddenly stops responding.
- Mouse continues to function outside of game in other window.

This only very recently started happening. No updates to nVidia, no updates to Windows. Could it have something to do with Patch 3.51?

I have to use the controller to log out of the game completely (quit only, logout doesn't change it). Then I get this: