Chinese universities poll students about teacher performance; these are little more than popularity contests. My student ratings are always the highest in the college; after these courses, it achieved new heights.

Perhaps your Chinese colleagues were jealous of your popularity among your students. So, in order to pay you back for that, they spread some malicious lies about you to the president to ensure you'd have to go once your contract came to its natural conclusion.

You're certainly not a person who hides his/her light under a bushel! Quite the opposite, in fact.