I'm describing a problem that happens since this MR: https://gitlab.com/ubports/development/core/lomiri/-/merge_requests/282 It happens with several of my apps like "Signal UT" and "Whatsnew" and others, but I will take here the example of whatsnew. ( https://github.com/pparent76/Whatslectron-UT ) Whatsnew is branded Whatsnew in the openstore, but in reality, for historical reasons the app id is "whatslectron.pparent" the Activity name is "whatslectron.pparent_whatslectron" and the XWayland window name that can be found with xdotool is "whatslectron". When the XWayland window is started the "X" icon still appears on the taskbar, ~~while we could expect it would be matched with the whatslectron.pparent app, with fuzzy string comparison.~~ Then when a secondary Qt/Wayland window is started by the app, it has for effect to make the main XWayland window invisible or ghost, while the "X" icon still remains in the taskbar, and the process is still running in ps, and the window is still there in xdotool. Opening a secondary Qt/Wayland window was working fine before the MR.