why is the user input showing as null?

Question

I have this code:

<h:form id="login">
                    <p:messages id="messages" globalOnly="true"/>

                    <h:panelGrid columns="3" cellpadding="5" style="margin: 0 auto;">

                        <p:outputLabel for="username" value="Username"/>
                        <p:inputText id="username" value="#{loginManager.username}"/>
                        <p:message for="username"/>

                        <p:outputLabel for="password" value="Password"/>
                        <p:inputText type="password" id="password" value="#{loginManager.password}"/>
                        <p:message for="password"/>

                        <p:commandButton id="submit" update="@form" value="Login" action="#{loginManager.submit}"/>
                    </h:panelGrid>
                </h:form>

and in the loginManager class which looks like this,

@Named
@RequestScoped
public class LoginManager {

@NotEmpty
@Size(min = 4, message = "Please provide a valid username")
private String username;

@NotEmpty
@Size(min = 5, message = "Please provide a valid password")
private String password;

@Inject
private SecurityContext securityContext;

@Inject
private ExternalContext externalContext;

@Inject
private FacesContext facesContext;

public void submit() throws IOException {
    
    System.out.println("username is " + username);
    System.out.println("password is " + password);

    // do something

}



public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

}

but when I click the login button, the sysout prints the values as null even though there were values I inputted before submit button was clicked. What is wrong with what I have set up? I am getting frustrated