When testing the 4.18.0rc1 client on rpi4 (Raspbian 12), I was unable to send any system keys to the server when in fullscreen mode (alt+tab, super key etc). It looks like this feature is broken on the wayland window managers available in Raspbian (Wayfire & Labwc). Switching to X11 solved this issue. To switch window manager, run > sudo raspi-config and go to "6 Advanced Options > Wayland".
Note that the behaviour is identical using client 4.17.0, and I'm positive that keyboard grab worked when we did release testing for 4.17.0.
Tested alt+tabbing with Remmina and RealVNC and could confirm that it only worked with X11. It seems like the protocol keyboard-shortcuts-inhibit-unstable-v1 [1] needs to be implemented for keyboard grabbing to work. Wayfire introduced this in v0.9.0 [2], and Raspbian packages version 0.7.5. We did not try to build/upgrade to a newer version to test if it would resolve the issue. Labwc, on the other hand, have not implemented the protocol, and seem to have taken some stance regarding it [3]. [1] https://wayland.app/protocols/keyboard-shortcuts-inhibit-unstable-v1 [2] https://github.com/WayfireWM/wayfire/commit/ada3a6ba2176134dc084cf373a38cd3521c1996d [3] https://github.com/labwc/labwc/issues/1046
labwc recommends using something called "ToggleKeybinds" [1] to get around this issue. I was able to make it work with tlclient by placing the following into $HOME/.config/labwc/rc.xml: > <?xml version="1.0"?> > <labwc_config> > <keyboard> > <keybind key="F12"> > <action name="ToggleKeybinds"/> > </keybind> > </keyboard> > </labwc_config> Pressing F12 toggles whether keybinds should go directly to the focused window instead. [1] https://labwc.github.io/labwc-actions.5.html#entry_action_name=togglekeybinds