I said "tried" because in fact 3M filed lawsuit in China against Huawei (which manufactured the 3N products). Surprisingly, the Chinese court found them guilty of infringement and even awarded damages to 3M.
Totally understood and not under debate. I could have been more clear.
"3N" is blatant infringement, or at least would be understood as such in the US. China simply doesn't enforce trademark infringement in the same way. I am not opining on whether China should.