Public bug reported:
## Summary
On Ubuntu 26.04 with GNOME 50/Wayland, Display Settings cannot mirror
the 1920x1200 internal laptop panel to a 1920x1080 external display.
“Join Displays” works normally, but selecting “Mirror” does nothing.
`gdctl` reports:
`Failed to create configuration: Different monitor resolutions within
the same logical monitor`
The system has split display routing: the internal eDP panel is driven
by NVIDIA, while the external DP/HDMI output is driven by Intel.
## System
- Ubuntu 26.04 LTS (Resolute)
- GNOME Shell 50.1
- Wayland session
- Kernel: 7.0.0-14-generic
- NVIDIA RTX PRO 2000 Blackwell Generation Laptop GPU
- NVIDIA open driver: 595.84
- Intel Arrow Lake-P integrated graphics
- Internal display: BOE 1920x1200 at 60 Hz on NVIDIA/eDP-1
- External display: 1920x1080 at 60 Hz on Intel/DP-3
Full package versions and GPU routing are included in the attached
diagnostics.
## Steps to reproduce
1. Boot into the Ubuntu GNOME Wayland session.
2. Connect a 1920x1080 HDMI display.
3. Open Settings → Displays.
4. Confirm that “Join Displays” works.
5. Select “Mirror.”
## Expected result
GNOME creates a mirrored desktop and scales the rendered image
appropriately for each physical display, keeping the internal panel at
its valid native 1920x1200 timing and sending a scaled 1920x1080 image
to the external display.
## Actual result
Nothing happens when “Mirror” is selected. The displays remain joined.
The equivalent `gdctl` command fails with:
`Failed to create configuration: Different monitor resolutions within
the same logical monitor`
## Diagnostic findings
Both displays and GPUs operate correctly in joined mode. The external
display is stable at 1920x1080, and the internal panel is stable at its
native 1920x1200.
The following were tested without changing the result:
- NVIDIA 595.84 and 595.91.07
- Mutter 50.1-0ubuntu2, 50.1-0ubuntu2.2, and 50.1-0ubuntu2.4
- Nouveau is blacklisted and not loaded
- NVIDIA DRM KMS is active
- No persistent Xorg configuration is present
- Ubuntu 26.04 provides no GNOME-on-Xorg session
As a diagnostic experiment, a temporary EDID override added a common
1920x1080 mode to the internal panel. GNOME then successfully created a
mirrored logical monitor containing both displays. This confirms that
the lack of a shared physical mode is the blocker.
However, the fixed-timing BOE internal panel cannot physically display
the synthetic 1920x1080 scanout correctly and repeats sections of the
image. The EDID experiment was completely removed, and the system was
returned to its original configuration before filing this report.
This indicates that Mutter needs a virtual/scaled clone mode: render one
mirrored desktop while retaining the native 1920x1200 scanout on the
internal panel and scaling the external output to 1920x1080.
## Related reports
This appears related to Ubuntu bug #2026228, “gnome-control-center
crashed when switching to mirror mode and monitors don't have matched
resolution,” and existing GNOME/Mutter reports concerning clone mode
with displays that lack a common physical resolution.
## Additional information
OBS can capture the internal display and present a correctly scaled
fullscreen image on the external display. Therefore, software-scaled
presentation is functional on this hardware; the limitation appears
specific to GNOME/Mutter’s native clone-mode construction.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: gnome-control-center 1:50.3-0ubuntu0.2
ProcVersionSignature: Ubuntu 7.0.0-14.14-generic 7.0.0
Uname: Linux 7.0.0-14-generic x86_64
NonfreeKernelModules: livepatch_livepatch_Ubuntu_7_0_0_14_14_generic_121
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Thu Sep 24 18:41:26 2026
InstallationDate: Installed on 2026-08-07 (49 days ago)
InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1)
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: gnome-control-center (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2168502
Title:
GNOME Wayland cannot mirror 1920x1200 internal display to 1920x1080
external display on split NVIDIA/Intel GPUs
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