There are two possibilities here:
- In the screen grab, we can only see part of the response, because it does not fit in the text box. Is it possible that there are some other characters present but out-of-sight, so that the answer is acutally wrong?
- There are complexities in Unicode (how Moodle stores text) which means that identical (to a human) strings can be stores in different ways. I don't know if this problem affects Chinese. Moodle should be able to cope with this. The Short-answer question type, which is used here, applies Unicode Normalisation before comparing strings. But, that might not be working in this case. https://en.wikipedia.org/wiki/Unicode_equivalence might explain the technical details. I don't know if you are able to test this possibility.