All of a sudden I can't open FULL SCREEN on my 4K 32in screen. I also have a Dell 30 in 1080 screen where it opens correctly. i used to be able to drag window to 4K and open it no problem. I just updated my Nvidia drivers (after the problem began) to ensure that was not it.
Never had an issue like this
Intel Core i7 Processor 5920k @3.5GHz
ASUS Rampage V Extreme 2011 v3 socket
Kingston Hyperx DDR4 RAM 32GB 2133 CL14
GeForce GTX 1080 TI
850 Watt PSU