** Description changed: On an external monitor, the top bar flickers where content updates regularly (clock, system-monitor-next extension). During the flicker, the wallpaper is visible instead of the panel, i.e. the region appears not to be painted in some frames. The internal display is not affected. Ubuntu 26.04.1 LTS, GNOME Shell / Mutter (GNOME Shell 50.1) Intel Panther Lake, xe kernel driver, kernel 7.2.0-070200rc1-generic External monitor via USB-C dock in DP Alt Mode (no DisplayLink, no MST) Scaling / refresh rates: internal: 166%, 120,00Hz; external: 100%, 59,99Hz - CLUTTER_PAINT=disable-clipped-redraws in ~/.config/environment.d/mutter-debug.conf fixes the issue completely. + CLUTTER_PAINT=disable-clipped-redraws in ~/.config/environment.d/mutter-debug.conf seems to fix the issue partly (less flickering). Not affected by disabling FBC, PSR or Panel Replay (xe.enable_fbc=0, xe.enable_psr=0, xe.enable_panel_replay=0), so the problem does not appear to be in the driver's damage-clip handling. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: gnome-shell 50.1-0ubuntu1.2 Uname: Linux 7.2.0-070200rc1-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Sep 24 13:10:00 2026 DisplayManager: gdm3 InstallationDate: Installed on 2026-07-04 (82 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) ProcEnviron: - LANG=de_DE.UTF-8 - PATH=(custom, no user) - SHELL=/bin/bash - TERM=xterm-256color - XDG_RUNTIME_DIR=<set> + LANG=de_DE.UTF-8 + PATH=(custom, no user) + SHELL=/bin/bash + TERM=xterm-256color + XDG_RUNTIME_DIR=<set> RebootRequiredPkgs: Error: path contained symlinks. RelatedPackageVersions: mutter-common 50.1-0ubuntu2.4 SourcePackage: gnome-shell UpgradeStatus: No upgrade log present (probably fresh install)
** Description changed: On an external monitor, the top bar flickers where content updates regularly (clock, system-monitor-next extension). During the flicker, the wallpaper is visible instead of the panel, i.e. the region appears not to be painted in some frames. The internal display is not affected. Ubuntu 26.04.1 LTS, GNOME Shell / Mutter (GNOME Shell 50.1) Intel Panther Lake, xe kernel driver, kernel 7.2.0-070200rc1-generic External monitor via USB-C dock in DP Alt Mode (no DisplayLink, no MST) Scaling / refresh rates: internal: 166%, 120,00Hz; external: 100%, 59,99Hz - CLUTTER_PAINT=disable-clipped-redraws in ~/.config/environment.d/mutter-debug.conf seems to fix the issue partly (less flickering). + CLUTTER_PAINT=disable-clipped-redraws in ~/.config/environment.d/mutter-debug.conf fixes the issue completely. Not affected by disabling FBC, PSR or Panel Replay (xe.enable_fbc=0, xe.enable_psr=0, xe.enable_panel_replay=0), so the problem does not appear to be in the driver's damage-clip handling. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: gnome-shell 50.1-0ubuntu1.2 Uname: Linux 7.2.0-070200rc1-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Sep 24 13:10:00 2026 DisplayManager: gdm3 InstallationDate: Installed on 2026-07-04 (82 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) ProcEnviron: LANG=de_DE.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> RebootRequiredPkgs: Error: path contained symlinks. RelatedPackageVersions: mutter-common 50.1-0ubuntu2.4 SourcePackage: gnome-shell UpgradeStatus: No upgrade log present (probably fresh install) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2168433 Title: Panel elements intermittently not drawn on external monitor (wallpaper shows through, flickering) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2168433/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
