If you are using Fcitx5 on Fedora KDE Wayland and Steam (Flatpak) refuses to show the input candidate window, follow these steps to fix the XWayland/XIM bridge. (Tested on Fedora KDE Plasma 43)
Fedora defaults to IBus, which often interferes with Fcitx5’s control over X11/XWayland input. Removing these ensures Fcitx5 has full control.
sudo dnf remove imsettings ibus