Unable to interact with game in full-screen mode

I had no problems yesterday, using the same settings, same drivers, same everything. I don't know what has changed.

The game launches fine, but when it's in full-screen mode I can't interact with it. The screen flickers like it's alt+tabbing or something, and then nothing. Right back to the start screen. I can't even change the settings to get to borderless windowed mode. I managed to work around this by using the nVidia GeForce Experience panel to alter the settings to be borderless windowed.

I'm using DX11, and I have the GeForce 364.72 drivers (the most recent ones) in SLI.