Hey, so I did some research and it might be your OS fault of not properly 'waking up'' your video card. I assume since you are using DP and HDMI that you have monitor connected to video card, right?
Funny thing is that in order to fix that, some guys wrote that you need to go to Control Panel > Power Settings and set "LInk State Power Management" to ''off''.
Can you try connecting your monitor to your Mobo instead? Maybe it has the legacy VGA connector and you happen to have older monitor that supports it and test it that way?
Anyway, the most valuable troubleshoot you can do right now is mentioned above - check if monitor works if connected with Mobo, instead of Video Card.
If so, then disable the previously mentioned setting.