drivers - Ubuntu doesn't recognize 2nd and 3rd HDMI monitors connected to NVIDIA GTX 1060

I have 3 HDMI monitors connected to a desktop running Ubuntu 16.10 with GNOME. One is through the integrated graphics card and is working properly. The other two are connected to the GTX 1060 and are not showing up anywhere.

I have tried nvidia-378, nvidia-375, and nvidia-370, but all fail to detect the two HDMI monitors connected to the graphics card.

Is there a way I can help the nvidia driver along by telling it where to look for the monitors?

Output of xrandr --query:

Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
VGA-1-1 disconnected
HDMI-1-1 disconnected
DP-1-1 disconnected
HDMI-1-2 disconnected
HDMI-1-3 connected primary 1920x1080+0+0 480mm x 270mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  

   1680x1050     59.88  
   1400x1050     59.95  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  

   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  

Output of lspci | grep VGA

00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06)
01:00.0 VGA compatible controller: NVIDIA Corporation GP106 [GeForce GTX 1060 6GB] (rev a1)

Output of lshw -C video

  *-display                 
       description: VGA compatible controller
       product: GP106 [GeForce GTX 1060 6GB]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0

       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:35 memory:f2000000-f2ffffff memory:e0000000-efffffff memory:f0000000-f1ffffff ioport:e000(size=128) memory:f3000000-f307ffff
  *-display
       description: VGA compatible controller
       product: Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
       vendor: Intel Corporation

       physical id: 2
       bus info: pci@0000:00:02.0
       version: 06
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:31 memory:f3400000-f37fffff memory:d0000000-dfffffff ioport:f000(size=64) memory:c0000-dffff