I tried Chinese words and English words, 500 returned.
I tried selecting 1.9 and 2.0 branch, the result is ok.
I tried selecting 2.0 and 2.1 branch on English and Traditional Chinese, the result is ok.
So, it seems that the bug only occurs when:
1. Simplified Chinese selected
2. Choose both 2.0 and 2.1 branch
The bug must hate me only!