To be fair, 1337x.tw is a fake 1337x domain [1, 2]. It's bad that it's even indexed by DDG higher than the official one, I think it would be better if it was completely hidden from results. The .tw is a malicious website that actively tries to mislead users. For example, on the main page it says "1337x.to is our main domain", but when you click on that, you get redirected to "1377x.to" (notice the swapped digit), yet another fake clone website that conveniently lists the .tw as one of the official mirrors.

Searching for site:1337x.to, which is the official domain, does give results.

[1]: https://1337x-status.org/

[2]: https://fmhy.net/unsafe#torrent-sites-clients, see "fake 1337x sites"