Vaadin and Apache Siro - Session ended

User logs in ok, logs out ok, but if he immediately makes another login attempt (login / pass + enter) he gets a popup

Session Expired
Take note of any unsaved data, and click here or press ESC key to continue.

      

        
        
        
      

    

Apache Shiro login:

Subject currentUser = SecurityUtils.getSubject();
currentUser.login(new UsernamePasswordToken(event.getLogin(), event.getPassword()));

      

        
        
        
      

    

Log out also:

Subject currentUser = SecurityUtils.getSubject();
currentUser.logout();

      

        
        
        
      

    

After logging out, the user is redirected to the login page, and when they re-enter their credentials, they receive an expired session warning. Why won't a new session start? How to start? Or maybe this approach is not quite right?

PS I've also tried

VaadinSession.getCurrent().close();

      

        
        
        
      

    

but the result was the same.