Cannot access web resources using spring reactive RouterFunction.resources() method

The following (simplified) code is deployed as a service.

@Configuration
public class RouterConfig {

    private static String htmlContent;

    static {
        try {
            InputStream res = new ClassPathResource("static/index.html").getInputStream();
            htmlContent = new String(res.readAllBytes());
        } catch (IOException e) {
            //
            System.out.println("ERROR");
        }
    }

    @Bean
    public RouterFunction<ServerResponse> indexRouter() {
        return route(GET("/"),
            request -> Optional.ofNullable(htmlContent)
                .map(content ->
                    ServerResponse.ok()
                        .contentType(MediaType.TEXT_HTML)
                        .bodyValue(content))
                .orElse(ServerResponse.status(HttpStatus.BANDWIDTH_LIMIT_EXCEEDED)
                    .build()));
    }

    @Bean
    public RouterFunction<ServerResponse> resourceRouter() {
        return RouterFunctions.resources("assets/**", new ClassPathResource("assets/"))
            .and(RouterFunctions.resources("fonts/**", new ClassPathResource("fonts/")))
            .and(RouterFunctions.resources("img/**", new ClassPathResource("img/")))
            .and(RouterFunctions.resources("/**", new ClassPathResource("/")));
    }
}

If I navigate to the root of my website then it can find the index.html file, which is great.

I defined a 'resource router' which is basically a RouterFunction which accesses my assets, fonts, imgs etc. (See code snippet)

However none of the resources are loaded into my website. Instead I get 404 errors :

My files in my jar file look like this :

And the resources are accessed from the index file like this :

How do you correctly configure assets when using spring-webflux Router Functions?