P2715Q works at 1440, but not higher

Hello,

I looked through other posts, but I haven't found anything like my problem.

My monitor works well at any resolution of 1440 or lower, but as soon as I try to increase the resolution, the screen goes black.  The computer, however, still recognizes the monitor.

I disabled Nvidia DSR, I disabled SLI, I installed the software, but nothing fixed it.

I set MST as secondary, and it works, but at a 30 Hz refresh rate, as primary it doesn't work at all, and when off, the maximum resolution that it will work at is 2560x1440 at 60Hz even though in the pc settings the recommended is 3840x2160.

SN: CN-032R1F-74445-4BR-928L

REV A00

Using a built desktop

Windows 8.1 Professional

2x Nvidia GTX 980 SLI

I'm using an HDMI to connect to my second monitor and a mDP for the P2715Q.

I bought the monitor from Newegg.