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I realize that this propably isn't Xfce problem at all, but...
I have set Onboard available at LightDM login from "/etc/lightdm/lightdm-gtk-greeter.conf": keyboard=onboard
I works fine, but when successfully logging in via Onboard and desktop is loaded, strange things start to happen. Any mouse click or keyboard special key action (for example pressing ALT) wreaks havoc. If I open home folder, suddenly all files are selected, they are opened and I have 20+ Thunar windows open, and this multiplies if I try to close any window with mouse, or trying to close something with ALT-F4 just triggers random properties-window open. If I open text editor the screen starts to scroll endlessly. Seemingly hitting ESC multiple times stops all this madness.
This reminds me of some old Windows-virus...
I doesn't matter if input event source is GTK or Xinput.
Debian 13 Stable, Xfce 4.20, onboard 1.4.1-10.
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