I'm so mad right now. I thought the error was from me.
I checked the changelog and I don't see how the 0.19.1 version Improved tokenizers/sentences/naive.

The module just returns an array of lowercased words, no more changes, just 1 array of same inputed sentence.

I seriously don't see how the module should be working on-site. I read the documentation, and the

tokenizers/sentences/naive works on-site in the documentation, but fails after install.