DESCRIPTION
As requested by Nate in https://bugs.kde.org/show_bug.cgi?id=521540#c21 this is a new report for my particular issue.

Since installing 6.7.0 (currently now on 6.7.2), I am seeing new system tray icons for apps that never had them before and have no need for such an icon, such as Firefox, VSCodium, Ungoogled Chromium, and KDE's own ISO Image Writer. These are all apps that I have installed as Flatpaks. These new icons don't appear for non-Flatpak apps.

STEPS TO REPRODUCE
1. Login to an X11 session in Plasma 6.7
2. Install a Flatpak app, such as KDE's ISO Image Writer
3. Run the app
4. Look at the system tray

OBSERVED RESULT
An icon appears for the app that was not there in previous Plasma versions. Left-clicking on the icon will open a new instance of the app. Right-clicking on the icon shows a menu with just "Quit <appname>", e.g. "Quit ISO Image Writer".

EXPECTED RESULT
No such icon to appear.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20260707
KDE Plasma Version: 6.7.2
KDE Frameworks Version: 6.27.0
Qt Version: 6.11.1
Kernel Version: 7.1.2-1-default (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION
This seems to (mostly) only happen in X11, but Wayland isn't completely immune. In Wayland, the icons don't appear most of the time, but they do appear briefly when logging in while a session is being restored. Once the session is restored, the icons disappear. That is, the icons appear briefly in Wayland while the app is being started, but this is most noticeable during a session restore.

I am running openSUSE Tumbleweed, which does not have AppArmor installed (old versions of Tumbleweed did, but they change to SELinux in 2025 for new installs).

plasmoidviewer -a org.kde.plasma.systemtray also shows the unexpected icons. I get a coredump when I close plasmoidviewer, by the way, but maybe that should be tracked elsewhere.