Qt virtualkeyboard cannot compose Korean on text-input-v3

Qt virtual keyboard has a problem to compose Korean in text-input-v3

When using TextInputManagerV3 in an example, fancy-compositor in qtwayland,

korean inputs are broken in a text field.

(The client having a text field should choose preferred text input protocol as text_input_v3
with QT_WAYLAND_TEXT_INPUT_PROTOCOL=zwp_text_input_v3)

When typing following charactors sequentially

ㅇ ㅏ ㄴ ㄴ ㅕ ㅇ

expected: 안녕

actual: ㅇ아안안ㄴ녀녕