[X11] Can not scale monitors in multi-monitor setup

[Lachlan Hogan]

Ubuntu 17.10
Gnome Shell Version: GNOME Shell 3.26.2
Mutter Version: 3.26.2-0ubuntu0.1

Preconditions: Two monitors (2560x1440 and 3840x2160)

Steps to reproduce:
 - Open gnome-control-center from command line
 - Navigate to Devices -> Displays
 - Change scale from 100% to 200% on either monitor

Expected:
 - Able to apply the scale changes to the monitor

Actual:
 - Receive error in the terminal:
   Config not applicable: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: Logical monitor scales must be identical

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it anymore. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.