I have an Asrock Vega 56 and an Asrock x470 Master (Windows 10) connected to a Dell U2414H via DisplayPort and when the PC goes to sleep and attempts to wake up the display on the monitor is black. The PC is awake because you can hear the beeps and response to mouse/keyboard events. The only way for me to wake up the PC is to pull the DP cable from the Vega and switch ports on the video card. I have upgraded the bios on the x470 to the latest and it had no benefit. Switching the ports on the monitor has no effect (only switching ports on the Vega).
Any thoughts on what to do?