did you try rice (very soft)? as my baby gal also reluctant to eat congee while she was around 10 months, as she saw us eating rice and want to try, so, she started to eat rice at that time la. don't give up.
hey, btw, did you change the brand of rice? i remembered i changed the brand of rice to cook congee and she really noticed it and reluctant to eat, after resuming the original brand of rice, she ate congee again.