Public bug reported:
Summary
Screen sharing in Chrome (Google Meet, "Entire screen" or "A Window")
flickers/corrupts for remote viewers while windows are being dragged during the
share. The local display never shows the flicker — it only appears in the
captured stream — which isolates this to Mutter's PipeWire screencast
implementation rather than actual GPU rendering or display output.
Steps to reproduce
1. Join a Google Meet call in Chrome on a Wayland/GNOME Shell session.
2. Click "Present now" → "Entire screen" (or "A Window").
3. Drag a window around the desktop while sharing.
4. Ask another participant on the call whether the shared screen flickers.
Expected behavior
The remote participant sees a stable video feed of the shared screen,
matching what's actually on the local display.
Actual behavior
The remote participant sees flickering/corruption, worst while windows
are actively being moved. The presenter's own screen looks completely
normal throughout.
Environment
- Ubuntu 26.04
- GNOME Shell / Mutter 50.1-0ubuntu1.3
- xdg-desktop-portal 1.21.1+ds-1ubuntu3.1, xdg-desktop-portal-gnome
50.0-0ubuntu1
- NVIDIA proprietary driver 580.178.04
- Session type: Wayland (XDG_SESSION_TYPE=wayland)
- Display scale: 100% (no fractional scaling)
- Chrome (latest stable), via chrome://flags/#enable-webrtc-pipewire-capturer
Troubleshooting already done (all ruled out as the cause)
- Sharing a Chrome Tab instead of the desktop/window does not flicker —
confirms the bug is specific to the portal/PipeWire desktop-capture path, not
Chrome's rendering or WebRTC encoding in general.
- Variable Refresh Rate: not enabled (gsettings get org.gnome.mutter
experimental-features does not include variable-refresh-rate).
- Disabled the xwayland-native-scaling Mutter experimental feature, logged
out/in, retested — no change.
- Disabled GNOME Shell animations (enable-animations false) — no change.
Additional notes
Happy to provide journalctl logs from gnome-shell/xdg-desktop-portal-
gnome during a reproduction, or test additional configurations, on
request.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: gnome-shell 50.1-0ubuntu1.3
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 12 23:09:41 2026
DisplayManager: gdm3
InstallationDate: Installed on 2023-10-09 (1099 days ago)
InstallationMedia: Ubuntu 22.04.2 LTS "Jammy Jellyfish" - Release amd64
(20230223)
RelatedPackageVersions: mutter-common 50.1-0ubuntu2.4
SourcePackage: gnome-shell
UpgradeStatus: Upgraded to resolute on 2026-05-18 (147 days ago)
** Affects: gnome-shell (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2170629
Title:
Screen share flickers for remote viewers (not locally) when moving
windows, on Wayland + NVIDIA 580 driver
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