High Sierra Dual Monitor Black Screen

GPU: Nvidia GeForce GTX 1080

MOBO: Gigabyte Z370

CPU: Intel i5 8400

Build: High Sierra (10.13.4)

Install method: Clover

NVidia Web Driver: 387.10.10.10.30.106

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I have previously been running a High Sierra setup fine with a single 4K Acer monitor connected via DP. I recently added an Acer 1440p 144hz monitor to my setup and am having issues running dual displays.

The 4K is now connected via HDMI, and the 1440p connected via DP. When OSX is booted only the 4K display works, with the 1440 remaining on a black screen. Additionally the 4K screen sometimes flickers on and off every 5 seconds or so depending on my config.plist settings.

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My initial graphics settings in config.plist were as follows:

<key>Inject</key> <dict> <key>ATI</key> <false/> <key>Intel</key> <true/> <key>NVidia</key> <false/> </dict> <key>NvidiaSingle</key> <false/> <key>ig-platform-id</key> <string>0x59120000</string> 

Based on troubleshooting posts I’ve came across, In trying to resolve the problem I have tried:

• Inject NVidia - True
• Inject Intel - False
• VideoPorts - 5
• VideoPorts - 2
• BootDisplay - 2
• BootDisplay - 1
• DualLink - 1

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I’ve also tried switching the DP port that the 1440p display is connected to, but that hasn’t made a difference. (I have FreeSync disabled on the 144hz display.)

Some combinations have been able to stop the flickering, or make OSX think there is a second display that I can drag windows over to, but the (1440) screen has always remained black.

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Any help would be greatly appreciated - currently thinking grabbing a second DP cable and eliminating the HDMI might be my next best guess.