TextFieldTTF not capturing system input method

Hi, I am using TextFieldTTF to capture player input text. It works fine with raw keyboard input. However, when I change the system input method, e.g. a Chinese input method for Chinese characters, the TextFieldTTF component show no character at all.
I use a customized Chinese font file for showing Chinese chars and it works normally with Label. I am using cocos2dx 4.0 on Deepin Linux.
Thanks for any help :slight_smile: