Every time I try to talk about Chinese censorship and injustices on that community though, they deny them or pretend I didn’t say anything.

Because you didn’t back up your claims at all, whereas other people replied to you with links that break down what you say as untrue yet you still keep saying them.

Nationalism is absolutely stupid and everyone needs to stop doing it.

Correct, that’s why most people here aren’t nationalist, and we certainly don’t welcome nationalists.