Dashboard filters won't show list of values for questions based on models



I have created a model to serve as base for all the questions in a dashboard.
One of the columns in the model represent the users name ("Membro"). This column metadata is properly set up and linked to the database table holding its data, as shown in the figure bellow.


I have created a few simple queries in the query builder, without using any SQL.


I then added those questions to a dashboard.


I want to filter this dashboard per user name. It seemed straightforward to add a "Text or Category" filter to it and link the filter to the "Membro" column in each question.
When I do it, the filter won't show em a list of options to select from. All it shows is a text box, where the users must guess exactly what to type in order to perform the filter.
I'm not sure what I'm doing wrong and couldn't find any help online. Can anyone point me in the right direction?
Here is a sequence of how I set up the dashboard filter:

I have the same issue, did you manage to fix it?