Can't filter content in a View

Hi!

First of all congratulations for backdrop. It is an amazing piece of software, I am totally loving it. 

I am trying to make something very simple. I have a content type called "Instituciones" (Institutions), and I want a view that displays all "Instituciones", but has a exposed filter in which the user can select to filter these instituciones by the "comuna" (county) they are in. Of course, "comuna" is one of the fields for content type "instituciones".

I create the view, and filtering by taxonomy works fine, but I just can't make the filter work with a "comuna". I have tried also filtering with a plain (not exposed) filter, and get the same (no) results. I here attach some screenshots. Please let me know if something else is needed. Thanks!