I counldn't find that tweet from a female streaming on Doyu that got a warning for featuring her white boyfriend, but found another news.

https://en.pingwest.com/a/6595

The stream was cutoff after a white guy appeared for a minute. If it’s not race detection, I don’t know what it is.

https://twitter.com/JoshuaDummer/status/1280877750245453828

https://www.taiwannews.com.tw/en/news/3963271