In the following page https://docs.spring.io/spring-security/reference/servlet/authentication/logout.html, I believe it should be :

this.logoutHandler.logout(request, response, authentication);

instead of :

this.logoutHandler.doLogout(request, response, authentication);

As the logout method name of SecurityContextLogoutHandler is logout.

Same for Kotlin example.