Do not plug HDMI and Display port in togther. The graphics card, Windows 10 and the monitor tend to get hung up and confessed and that it has two monitors connected. .When you set the monitor for Display Port set the refresh rate and then press the toggle setup bottom to restart/reset the monitor. Check your graphics card setting afterward to insure the are set to the same settings as your monitor it set to. I finality got the Display port and the HDMI input to be plugged in at the same time, but I would suggest only the Display port so you can get the 100 hz refresh rate at 1340 x1440.
Good Luck