CompletionContributor not working

Hello,

I have a plugin I am working on: https://github.com/ourPLCC/plcc-intellij 

I am trying to implement a basic proof of concept for completion for my language based on the example in the platform SDK documentation. Here is my code:

Registering contributor:

Language recognition works, but when I start typing "Hello" in the place where a PLCCTypes.REGEX is expected, no autocompletion pop-up shows up.

I even know a REGEX token is expected because the red squiggly lets me know:

But when I start typing, nothing shows up. I even tried to do Ctrl + space, Nothing

Does anyone have anything I could try?

Thanks