Dual monitor issues in Ubuntu 18.04

Question

I just made a clean installation of Ubuntu 18.04 and I am facing issues with dual monitors.

I have a desktop with Intel® Xeon(R) CPU E5-1660 v4 processor and 64GB RAM. I have two monitors, both are Dell 24".

When I turn the computer on, both the monitors are detected and I can see the BIOS screen on both of them. When the login screen is about to be displayed, one of the monitors turns off and does not recover. To make things worse, the monitor that turns off is detected as the primary.

Even when I connect this monitor after the computer is turned on, it does not automatically start to function. It works only if I go to the display settings, change the display mode to "Mirror" and back to "Join Displays".

Driver:

$ lshw -c video

  *-display                 
        description: VGA compatible controller
        product: GM107GL [Quadro K1200]
        vendor: NVIDIA Corporation
        physical id: 0
        bus info: pci@0000:03:00.0
        version: a2
        width: 64 bits
        clock: 33MHz
        capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
        configuration: driver=nouveau latency=0
        resources: irq:30 memory:f6000000-f6ffffff memory:e0000000-efffffff memory:f0000000-f1ffffff ioport:e000(size=128) memory:f7000000-f707ffff

xrandr output:

Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 16384 x 16384
DP-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 527mm x 296mm
    1920x1080     60.00 +  60.00*   50.00    59.94    24.00    23.98  
    1920x1080i    60.00    50.00    59.94  
    1600x1200     60.00  
    1280x1024     75.02    60.02  
    1152x864      75.00  
    1280x720      60.00    50.00    59.94  
    1024x768      75.03    60.00  
    800x600       75.00    60.32  
    720x576       50.00  
    720x576i      50.00  
    720x480       60.00    59.94  
    720x480i      60.00    59.94  
    640x480       75.00    60.00    59.94  
    720x400       70.08  
DP-2 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 519mm x 324mm
    1920x1200     59.95*+
    1600x1200     60.00  
    1680x1050     59.88  
    1280x1024     75.02    60.02  
    1152x864      75.00  
    1024x768      75.03    60.00  
    800x600       75.00    60.32  
    640x480       75.00    59.94  
    720x400       70.08  
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 disconnected (normal left inverted right x axis y axis)

Any ideas on how to fix this will be greatly appreciated.

Solution

I've had similar issues before. Turns out you can change the primary monitor using Nvidia settings, if you are using the proprietary driver.

Just open Nvidia settings, go to displays, and then choose how you want your monitors laid out. Then save your settings. It should preserve your settings on reboot.

If it does not, you can save the settings to the xorg configuration from within the same application. This will ask you for your password as it requires root access.

I'm on my phone so I cannot provide a screenshot or better formatting.