Do you mind checking l̶i̶c̶h̶e̶s̶s̶.̶c̶o̶m̶ lichess.org? It's a popular online chess website, as the name suggests. A Reddit post from a month ago claims it is also blocked. [1] I think that would be hilarious.
[1]: https://old.reddit.com/r/tmobile/comments/r0r2jh/tmobile_blo...