Packaging scss in addon doesn't work

Hi,

I try to package scss in an addon but it doesn't work...
I followed the wikki page https://vaadin.com/wiki/-/wiki/Main/Packaging+SCSS+or+CSS+in+an+add-on

I created a test project using the vaadin-archetype-widget. My artifactId is named as widget-test.
So I created VAADIN/addons/widget-test/widget-test.scss in Resources folder.
Then I added in the pom.xml in manifestEntries block: <Vaadin-Stylesheets>VAADIN/addons/widget-test/widget-test.scss</Vaadin-Stylesheets>
After running mvn install, I can see in the jar the VAADIN/addons/widget-test/widget-test.scss and the entry <Vaadin-Stylesheets>VAADIN/addons/widget-test/widget-test.scss</Vaadin-Stylesheets> in the MANIFEST.MF.

The jar is imported automatically in the project widget-test-demo. Normally the addons.scss file should have been updated automatically but it's not updated... I add manually the entry in the addons.scss:

/* This file is automatically managed and will be overwritten from time to time. */
/* Do not manually edit this file. 
@import "../../../VAADIN/addons/widget-test/widget-test.scss";

/* Import and include this mixin into your project theme to include the addon themes */
@mixin addons {

    @include widget-test;

}

When I run the project  widget-test-demo, the scss is not displayed...

Am I missing something?
Thanks