SUMMARY

There are some applications that provide a "minimize to system tray" functionality where "closing" the application window (by the Ⓧ in the title bar) should actually only close the application window and let the application running in the background maintaining its icon in the task bar. An example of this is the spotify application.

Until recently, this used to work. After an upgrade to plasma 6.5 it does not anymore. The Ⓧ button has simply become a NO OP and trying to close from the task manager is the same.

Note that the Ⓧ has no visible outcome on plasma, but the applications themselves get to think that the main window is closed. The spotify client is an excellent example of this because the systray icon notifies the window state. When spotify thinks its main window is open the systray icon provides an option to "Minimize to tray" and when spotify thinks its main window is close the systray icon provides the option to "Show Spotify".

Not 100% sure this is really a regression even if it looks very much like one. It may be the case that the application has merely moved to operate as a wayland application and it would not be a surprise if — as we are now used to — wayland breaks useful behaviors by policy (e.g. wayland developers knowing better that applications should not ever be able to close their main window because).

In any case, this used to be a quite useful behavior to avoid polluting the taskbar, so please try to see if it can be restored either fixing a regression or working around wayland limitations. Hopefully it would be great if this could be fixed before after two more years the wayland developers accept that applications closing their main window and leaving only the systray icon is not an extra dangerous behavior but something that can be accepted in the protocol ;-) 


STEPS TO REPRODUCE

Spotify is the easiest reproduction case.

1. Install the official spotify client
2. Start it
3. Go to settings and activate "close button should minimize the spotify window [to system tray]" in the "Startup and window behavior" section
4. Try to close the application

OBSERVED RESULT

The application window does not close, but the systray icon gets to think that the application main window is closed (now it says "show spotify" rather than "minimize to system tray"). 

EXPECTED RESULT

The application should work as intended by letting its main window be closed leaving the app running in the background with an indication of that in the systray.


SOFTWARE/OS VERSIONS

Operating System: Manjaro Linux 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.17.13-1-MANJARO (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-4750HQ CPU @ 2.00GHz
Memory: 16 GiB of RAM (15.5 GiB usable)
Graphics Processor: Intel® Iris® Pro Graphics P5200
Manufacturer: Notebook
Product Name: W740SU

ADDITIONAL INFORMATION