Chinese Input Stopped working in ubuntu 18.04LTE

I had Chinese input with IBUS working for long time. Recently the Chinese input started having some problems. When the problem started a week or two ago, the first, the input method worked, shows the candidates, input the my choices, then after a few Chinese characters, it stopped mapping my choice number into Chinese character, just put the number into the document.

But now the input method completely stopped working, doesn’t even switch to the Chinese input mode.

I removed and reinstalled Chinese, IBUS, restarted so many times without any success.

What else can I do?