The official Flutter pages have a link near the upper right corner for filing a bug about issues in the page. The flutterchina pages are keeping that link as-is, which is resulting in people filing bugs in Flutter's issue tracker, which are just closed since it's not an official Flutter site. See:
https://github.com/flutter/flutter/issues?utf8=%E2%9C%93&q=is%3Aissue+flutterchina
It would make a lot more sense for that link to point to your issue tracker.