When using nVidia Settings to set up a 3 display setup (xorg.conf in question is attached) it seems that the settings aren't saved to xorg.conf across reboots or logouts. DRobbins gave me something to try (creation of /etc/dbus-1/session.d/mutter.conf) that seems to have worked for him, but it doesn't work for me. In the reproduction steps I'll refer to the different settings daemons in play in/with this bug as G-S-D and N-S. Please resolve this issue as soon as you can see what's wrong because I'll inevitably need to restart my computer when messing with my kernel to add a feature / to upgrade to a newer version and I don't want t have to reset up my displays each time that happens. Thanks in advance.

The GPU in use is a GTX 1060 3GB.

G-S-D Version: 3.36.1

nVidia Drivers/Kernel Modules version: 440.100

What works: I can set it all up how I like and all is fine, but when the need arises to reboot or log out the settings are gone and the efforts of getting it setup to begin with are wasted.

What doesn't work: rebooting and expecting the displays to be set up as you left them pre-reboot.

Contents of aforementioned mutter.conf drobbins had me try:

<!DOCTYPE busconfig PUBLIC
"-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
"http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
<policy context="default">
<deny receive_interface="org.gnome.Mutter.DisplayConfig" receive_member="ApplyMonitorsConfig"/>
</policy>
</busconfig>