Thank you. While this is irritating I can live with it (alas I do not have access to any Dell docking station for this computer). And I need to use the Nvidia GPU and am right now unable to move to 26.04. So I have to be a bit "masochistic" for a while. ;-)
Good to know that this is (most likely) a known issue which should mean that you can close this bug report? 2026-06-11 07:07 skrev Daniel van Vugt: > It looks like this is related to Xrandr-based fractional scaling. That > distributes the scaling responsibility between Xorg and Mutter (gnome- > shell). It worked, but had some edge cases not dissimilar to this bug. > To test this theory, you can try disabling Fractional Scaling under > Settings > Screen Display. > > Long term, the solution is Wayland native fractional scaling. While > that > does exist in Ubuntu 24.04, complete support for Nvidia with Wayland > does not. Ubuntu 26.04 resolves all of this. > > If you are unable to move to Ubuntu 26.04, then a possible solution for > 24.04 is to use only display connectors wired to the integrated Intel > GPU and then select the Wayland session (not Xorg) on the login screen. > You might be able to do that by avoiding the HDMI port and using > Thunderbolt port adapters instead. As I understand it, the "Dell Pro > Max > 16 Plus" has two such compatible ports on the left side next to the > HDMI > port. > > ** Package changed: xorg (Ubuntu) => mutter (Ubuntu) > > ** Summary changed: > > - Wrong resolution on primary (laptop) screen after turning on external > 4K monitor > + [xorg] Wrong resolution on primary (laptop) screen after turning on > external 4K monitor > > -- > You received this bug notification because you are subscribed to the > bug > report. > https://bugs.launchpad.net/bugs/2156353 > > Title: > [xorg] Wrong resolution on primary (laptop) screen after turning on > external 4K monitor > > Status in mutter package in Ubuntu: > New > > Bug description: > I have a laptop (1920x1200) and an external monitor connected via > HDMI > (3840x2160) and I had locked my computer and turned off my external > monitor. Note that I have previously configured Ubuntu to never send > "power save" signal to external monitor as Gnome interpreted this as > if I had physically removed the external display (this is a known > problem as I understand it -- this bug report is *not* about that > issue (but it might be related in some way)). > > Note that I have Fractional Scaling enabled and laptop display is set > to 100% scaling and external 4K monitor is set to 150% scaling. > > Initial state is thus laptop running Ubuntu that is attached to an > external 4K monitor. After screen was locked (via Windows-l key > combination) external monitor was turned off (via physical button on > monitor). Laptop screen shows login dialog with correct resolution. > > To trigger the bug I turn on the external 4K monitor (via physical > button). This results in external monitor going on but showing a > black > picture. The laptop monitor (with login dialog) is scaled as if it > showed a 4K image on the 1920x1200 screen (you almost need magnifying > glasses to be able to see what you are doing on that screen). After > entering my password the laptop screen is unlocked (but still showing > the scaled resolution) and external monitor still shows a black > picture. Entering Ubuntu Settings App, selecting Displays and > clicking > on my external monitor revealed that it had been disabled! Enabling > external monitor reset the resolutions of the monitors to what I > expected (and open applications are placed on the correct monitor). > > Expected behavior is Ubuntu/Gnome *not* disabling the external > display > when its power is turned off (via physical button on monitor) as it > is > still electrically connected via HDMI-cable and monitors power cord > is > still connected to the wall socket. > > ProblemType: Bug > DistroRelease: Ubuntu 24.04 > Package: xorg 1:7.7+23ubuntu3 > ProcVersionSignature: Ubuntu 6.17.0-35.35~24.04.1-generic 6.17.13 > Uname: Linux 6.17.0-35-generic x86_64 > .proc.driver.nvidia.capabilities.fabric-imex-mgmt: > DeviceFileMinor: 4323 > DeviceFileMode: 256 > DeviceFileModify: 1 > .proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular > file. > .proc.driver.nvidia.capabilities.mig: Error: path was not a regular > file. > .proc.driver.nvidia.gpus.0000.02.00.0: Error: path was not a regular > file. > .proc.driver.nvidia.registry: Binary: "" > .proc.driver.nvidia.suspend: suspend hibernate resume > .proc.driver.nvidia.suspend_depth: default modeset uvm > .proc.driver.nvidia.version: > NVRM version: NVIDIA UNIX Open Kernel Module for x86_64 580.159.03 > Release Build (dvs-builder@U22-I3-AM27-29-6) Fri Apr 24 06:03:03 UTC > 2026 > GCC version: gcc version 13.3.0 (Ubuntu 13.3.0-6ubuntu2~24.04.1) > ApportVersion: 2.28.1-0ubuntu3.8 > Architecture: amd64 > BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log' > CasperMD5CheckResult: pass > CompositorRunning: None > CurrentDesktop: ubuntu:GNOME > Date: Wed Jun 10 14:14:42 2026 > DistUpgraded: Fresh install > DistroCodename: noble > DistroVariant: ubuntu > ExtraDebuggingInterest: Yes > GraphicsCard: > Intel Corporation Arrow Lake-U [Intel Graphics] [8086:7d67] (rev 06) > (prog-if 00 [VGA controller]) > Subsystem: Dell Device [1028:0d12] > NVIDIA Corporation Device [10de:2c39] (rev a1) (prog-if 00 [VGA > controller]) > Subsystem: Dell Device [1028:0d12] > InstallationDate: Installed on 2026-05-02 (39 days ago) > InstallationMedia: Ubuntu 24.04.4 LTS "Noble Numbat" - Release amd64 > (20260210) > MachineType: Dell Inc. Dell Pro Max 16 Plus MB16250 > ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.17.0-35-generic > root=UUID=8b298203-7cbd-41d8-a9f0-ebda6018a14b ro quiet splash > vt.handoff=7 > SourcePackage: xorg > Symptom: display > UpgradeStatus: No upgrade log present (probably fresh install) > dmi.bios.date: 11/19/2025 > dmi.bios.release: 2.2 > dmi.bios.vendor: Dell Inc. > dmi.bios.version: 2.2.2 > dmi.board.name: 0K8XPY > dmi.board.vendor: Dell Inc. > dmi.board.version: A01 > dmi.chassis.type: 10 > dmi.chassis.vendor: Dell Inc. > dmi.ec.firmware.release: 1.3 > dmi.modalias: > dmi:bvnDellInc.:bvr2.2.2:bd11/19/2025:br2.2:efr1.3:svnDellInc.:pnDellProMax16PlusMB16250:pvr:rvnDellInc.:rn0K8XPY:rvrA01:cvnDellInc.:ct10:cvr:sku0D12: > dmi.product.family: Dell Pro Max Laptops > dmi.product.name: Dell Pro Max 16 Plus MB16250 > dmi.product.sku: 0D12 > dmi.sys.vendor: Dell Inc. > version.compiz: compiz N/A > version.libdrm2: libdrm2 2.4.125-1ubuntu0.1~24.04.1 > version.libgl1-mesa-dri: libgl1-mesa-dri 25.2.8-0ubuntu0.24.04.1 > version.libgl1-mesa-glx: libgl1-mesa-glx N/A > version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A > version.xserver-xorg-core: xserver-xorg-core 2:21.1.12-1ubuntu1.5 > version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A > version.xserver-xorg-video-ati: xserver-xorg-video-ati > 1:22.0.0-1build1 > version.xserver-xorg-video-intel: xserver-xorg-video-intel > 2:2.99.917+git20210115-1build1 > version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau > 1:1.0.17-2ubuntu0.1 > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2156353/+subscriptions -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2156353 Title: [xorg] Wrong resolution on primary (laptop) screen after turning on external 4K monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2156353/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
