Japanese IME (Mozc) input doesn't work for me in Linux

Godot Version

v4.7.1.stable.arch_linux [a13da4feb]

Question

Context: I am running Godot under Arch with KDE Plasma.

This applies to both the editor and running scenes. When I set my IME to Japanese input mode, the keys I type are still captured as Latin characters. Furthermore, my system shortcut to toggle between English and Japanese input (Ctrl+Space) is intercepted by Godot and not allowed to pass through to my OS.

Related Issues

This is different from the issues listed below, because IME input is not working at all for me.

Hello, I have tested it on Debian 13 with KDE on Wayland using Fcitx5, and on Arch Linux with XFCE on X11 using Fcitx5. It works fine on both of them, although IME popup sometimes has incorrect position. Which input method you are using (e.g. Fcitx5)? Are you using X11 or Wayland? Does IME work well on other application (e.g. made with GTK, Qt or other native apps)? Does changing system shortcut from Ctrl+Space to, for example, Super+Space prevents shortcut being intercepted by Godot?