17.10 - multi-monitor screen positions are not saved

wayland, gnome-shell, 17.10, up-to-date system.

It seems my monitors.xml is not consulted on gdm launch/session launch, either wayland or X. I have two monitors, and I want to place one on the right and one on the left. This isn't working, I just get the default sort, which, of course is wrong.

I've attached standard apport-collect information, I'm willing to debug more, but it's just plain not working for me right now.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-shell 3.26.1-0ubuntu4
ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4
Uname: Linux 4.13.0-16-generic x86_64
ApportVersion: 2.20.7-0ubuntu3
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Oct 20 21:23:53 2017
DisplayManager: gdm3
GsettingsChanges:
 b'org.gnome.shell' b'enabled-extensions' b"['<email address hidden>', 'system-monitor', '<email address hidden>', '<email address hidden>', '<email address hidden>', '<email address hidden>']"
 b'org.gnome.shell' b'favorite-apps' b"['terminator.desktop', 'google-chrome.desktop', 'org.gnome.Nautilus.desktop', 'firefox.desktop']"
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
 b'org.gnome.desktop.interface' b'clock-show-date' b'true'
InstallationDate: Installed on 2017-10-03 (17 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170926)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)