S2716DG, DP port stopped working, #2

This hard reset helped, thanks! I removed the HDMI and did a hard reset of the power button on the monitor (had removed all cables from the monitor). I did not turn off the PC. On connecting only the Display cable to my PC, and powering the monitor back on after connecting the power cable, the monitor was able to function via the Display port! The G Sync option is now visible in the Nvidia control panel as well.