Editorconfig not warning about indentation - ubuntu-16.04

Question

I discovered editorconfig but I cannot get it to notify me about incorrect indentation.
I installed editorconfig on ubuntu 16.04:
editorconfig -v
EditorConfig C Core Version 0.12.0
In a directory, I setup the configuration within an .editorconfig file:
root = true
[*]
charset = utf-8
end_of_line = lf
indent_style = space
indent_size = 2
insert_final_newline = true
trim_trailing_whitespace = true
Then I create a text file test.txt only using 1 space for indentation:
This is a test.
It only uses one space.
I would like editorconfig to notify me.
Because I set it to have 2 spaces.
When I run the command:
editorconfig $(pwd)/test.txt
I just get the config back:
charset=utf-8
end_of_line=lf
indent_style=space
indent_size=2
insert_final_newline=true
trim_trailing_whitespace=true
tab_width=2
When I open the file in atom (with the atom editorconfig plugin installed and activated), I do see the mouse icon down in the status bar. It warns me about the whitespace package.
When I deactivate the atom whitespace package, I don't see any icon in the nav bar.
Still in atom, when I use the command EditorConfig: Show State I get a green notification telling me that everything is ok.
When I use the command EditorConfig: Fix file, I get:
The file test.txt conformed to the end_of_line and indent_style properties. No changes were applied.
I looked all over the place in the documentation and on the internet.
I've spent about an hour on this thing.
I don't get it.
Clearly the indentation is incorrect.
Still, why can't I get any notification?
What am I obviously missing?