My U2518D refuses to go to the full native resolution on Windows 7, using DisplayPort and Nvidia GTX 960. Windows selects 1920x1080. Works as expected on HDMI. Auto selects 2560x1440. Current NVIDIA driver, current Windows patches, current firmware (M2T103) on monitor. The U2518D handled WQHD over DP just fine previously (FreeBSD and Nvidia 1050), so I'd guess it is a windows problem? Or cabling? HDMI is a suitable workaround, but I hate mysteries and prefer to use DP whenever I can. Any help?