Spring Boot custom favicon.ico not showing

I solved this problem by putting favicon.ico in main/resource/static and adding this lines to my security config

 httpSecurity
            .authorizeRequests()
                .antMatchers( "/favicon.ico").permitAll()

I have this with SpringBoot configuration too and is working

<link rel="shortcut icon" type="image/png" th:href="@{/img/favicon.png}"/>

And the favicon.png under resources/public/img