Public bug reported:
On Ubuntu 26.04 with GNOME Shell 50.1 running under Wayland, several Qt
applications lose their window shadows and rounded corners when using
the native Wayland backend.
The same applications display shadows and rounded corners correctly when
forced to use XWayland (QT_QPA_PLATFORM=xcb).
This appears to be a general Qt/Wayland integration issue rather than an
application-specific bug.
Environment
Ubuntu 26.04
GNOME Shell 50.1
Wayland session
gnome-shell --version
GNOME Shell 50.1
echo $XDG_SESSION_TYPE
wayland
gsettings get org.gnome.mutter experimental-features
['scale-monitor-framebuffer', 'xwayland-native-scaling']
Affected applications
Examples include:
KeePassXC
Git Cola
The issue is reproducible with multiple Qt applications.
Observed behavior
When launched normally (native Wayland):
no window shadow
no rounded corners
When launched with:
QT_QPA_PLATFORM=xcb <application>
the same applications immediately regain:
window shadow
rounded corners
No other changes are required.
Qt plugin verification
Native Wayland:
libqwayland-generic.so
Forced X11/XWayland:
libqxcb.so
This suggests the difference is related to the Qt Wayland backend rather
than the applications themselves.
Additional notes
Initially, Git Cola installed through pipx appeared to have the correct
window decorations. After further investigation, the determining factor
was not the installation method, but the backend being used (Wayland vs
XWayland).
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: qtwayland5 5.15.18-1
ProcVersionSignature: Ubuntu 7.0.0-27.27-generic 7.0.6
Uname: Linux 7.0.0-27-generic x86_64
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jun 29 08:40:23 2026
InstallationDate: Installed on 2026-06-15 (14 days ago)
InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1)
ProcEnviron:
LANG=pt_BR.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
SourcePackage: qtwayland-opensource-src
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: qtwayland-opensource-src (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2158616
Title:
Qt applications running natively on Wayland lack window shadows and
rounded corners on Ubuntu 26.04
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