Visiting variant slug will show page not found

[sakurs2]

I use gitbook to host markdown documents, the domain is "xxx.github.io/docs", I add the slug "latest" for the main page, so "xxx.github.io/docs/latest" should also be visited.

But I can only just visit "xxx.github.io/docs", when I visit "xxx.github.io/docs/latest" I got "page not found" error, which seems like the sever want find the document named "latest", so how to make "xxx.github.io/docs/latest" can be visited normally?