https://bugzilla.redhat.com/show_bug.cgi?id=1627552
--- Comment #4 from sam skynare@gmail.com --- I changed ibus-setup so that ibus-hangul starts in Hangul mode, eliminating the need to type Shift-space.
ibus-setup
to start IBus Preference dialog Input Method tab > Korean - Hangul > Preferences > check Start in Hangul mode