What does apache Netbeans 12 tip for CDI "The element is not managed bean" mean?

I'm working on a new JEE8 project using Netbeans 12 as IDE and every thing work but I have a strange tip that goes like this:

the element is not managed bean it has qualifiers but implements javax.enterprise.inject.spi.Extension

on classes marked as:

@javax.inject.Named
@javax.faces.view.ViewScoped
public class ProjectsView implements Serializable {
    public static final long serialVersionUID = -1L;
    @Inject
    private ProjectService service;
      ...

My code works fine on server, the application works as intended but I want to understand what this tip mean?

here is a picture:

EDIT ADDITIONAL INFO:

this only appears if you set source to 14 in POM.xml maven compiler plugin

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>14</source>
                    <target>14</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>