Primary Monitor Keeps Changing To Secondary Display

I am having a bizarre issue with my dual monitor setup on Zorin Core 15.3. I have one primary monitor and a secondary monitor I use for controlling multimedia, having another thing to read off of, etc. Zorin originally defaulted to making my secondary monitor the primary monitor, which I then changed using NVIDIA X-Server settings and saved the configuration to the xorg.conf file. However, every time I reboot to Zorin from another OS, the configuration resets to using my secondary monitor as my primary monitor again, and sometimes when I am using Zorin after resetting my display configuration back to what it is supposed to be, my computer freezes up for some time, refreshes my screens, and goes back to using my secondary monitor as the primary display.

Has anyone had this issue before? If so, is there a fix for it? Below is my xrandr output:

Screen 0: minimum 8 x 8, current 3840 x 1200, maximum 32767 x 32767
DVI-D-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 299mm
1920x1080 60.00*+ 59.99 59.94 50.00 60.05 60.00 50.04
1680x1050 59.95
1600x1200 60.00
1440x900 59.89
1366x768 59.79
1280x1024 75.02 60.02
1280x960 60.00
1280x720 60.00 59.94 50.00
1152x864 75.00
1024x768 75.03 70.07 60.00
800x600 75.00 72.19 60.32 56.25
720x576 50.00
720x480 59.94
640x480 75.00 72.81 59.94 59.93
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 connected primary 1920x1200+1920+0 (normal left inverted right x axis y axis) 550mm x 340mm
1920x1200 59.95*+
1920x1080 59.94 50.00 60.00 50.04
1680x1050 59.95
1440x900 59.89
1440x576 50.08
1280x1024 75.02 60.02
1280x960 60.00
1280x720 60.00 59.94 50.00
1152x864 75.00
1024x768 75.03 70.07 60.00
800x600 75.00 72.19 60.32 56.25
720x576 50.00
720x480 59.94
640x480 75.00 72.81 59.94 59.93
DVI-D-1 disconnected (normal left inverted right x axis y axis)

Two questions:

  1. Can you try selecting the primary monitor through Zorin menu -> Settings -> Devices -> Display?
  2. Do you have two GPUs?

Okay, I am incredibly stupid and only just found the option to do it in Settings just now. I just did it in there, I’ll let you know if it happens again.