U3415W not leaving standby mode on cold boot, always works on reboot

So I discovered a quirk with my new U3415W but I am not 100% sure if it's monitor or GPU related. I am using a GTX980ti video card.

I have my new U3415W into Displayport 1 on the video card and it displays and looks absolutely great.

However, when I do a cold boot of the PC, the monitor never goes off of power saving/standby mode, just like it doesn't have a signal. I just have the slow steady pulse of the standby light even though the computer has completely booted. Now if I wait until the PC boots and press the power button on the case to turn it off (I have it set to turning the power off) , THEN hit the button again and it boots up just fine, I can see the bios splash and everything right from the get go.

Happens each and every time.

Any idea what's going on?

Video card was on HDMI before with my old monitor and this never happened with it, only since I moved the the fancy new monitor and displayport cable.