I doubt its a problem with search. It looks more like censorship to me. Just like if you are not logged in certain words are censored now like...
I found the tag now, but only because it was a tag under one of the notable stories from backers. The family one. Still cant find it through...
There are no stories found on the main page under the tag family, or non-con for that matter.
Separate names with a comma.
