One more guestion about the X34 OD issue + gsync issue

I just want to make sure where the problem really is before I sent my monitor back to the seller. (Monitor bought in November 2015)

Max OD 95 Hz ( latest nVidia driver, 980 ti xtreme gaming SLI)

If I try to set 100 Hz in the nVidia CP my monitor goes black for around 5 seconds and then returns to the previous setting, 95 Hz. Monitor menu however shows that the slider is at it max, showing 100 Hz. The information menu shows 95 Hz.

The DP cable is original.

gsync... I have noticed tearing + slide show effect in every games I play. When gsync is on the FPS are somewhere 140+. I have thought that when gsync is on FPS and Hz are in sync. Shouldn't it be that way? I have also tried to eliminate tearing by locking manually FPS at 100 or 95, 90, 85 and so on. Tearing still occurs no matter what the settings are.

So are these the very known issues with the monitor or could there be a problem with my gfx card or somewhere else in my PC?

Thanks in advance.