https://bugzilla.redhat.com/show_bug.cgi?id=1154526
--- Comment #10 from fujiwara tfujiwar@redhat.com --- (In reply to Marko Myllynen from comment #9)
Sorry, you're right. gnome-settings-daemon still checks if the input sources include ibus engines while gnome-shell always runs ibus-daemon and it tracks the value of gsettings org.gnome.desktop.interface gtk-im-module.
The workaround is still needed or export GTK_IM_MODULE=ibus in .profile.