MP Rest client don't work correctly with CompletionStage and RX data types

@Path("/")
public interface RxTestInterface {
    @GET
    @Path("normal")
    Single<String> normalSingle();

    @GET
    @Path("normal")
    String normalString();

    @GET
    @Path("normal")
    CompletionStage<String> normalCs();
}

@Path("/")
public class Resource {
    @GET
    @Path("normal")
    public String normal() {
        return "resteasy";
    }
}

public class App {
    public static void main(String[] args) throws Exception {
        ResteasyClient client = (ResteasyClient) ClientBuilder.newBuilder().build();
        RxTestInterface proxy = client.target("http://127.0.0.1:8080/jaxrs-wf").proxy(RxTestInterface.class);
        CompletionStage<String> cs = proxy.normalCs();
        System.out.println(cs.toCompletableFuture().get());
        Single<String> single = proxy.normalSingle();
        single.subscribe((String s) -> {
            System.out.println(s);
        });
        client.close();
    }
}

public class App {
    public static void main(String[] args) throws Exception {
        RxTestInterface mpRestClient = MicroprofileClientBuilderResolver.instance()
                .newBuilder()
                .baseUrl(new URL("http://127.0.0.1:8080/jaxrs-wf"))
                .build(RxTestInterface.class);
        String s = mpRestClient.normalString();
        System.out.println(s);
    }
}

public class App {
    public static void main(String[] args) throws Exception {
        RxTestInterface mpRestClient = MicroprofileClientBuilderResolver.instance()
                .newBuilder()
                .baseUrl(new URL("http://127.0.0.1:8080/jaxrs-wf"))
                .build(RxTestInterface.class);
        CompletionStage<String> cs = mpRestClient.normalCs();
        System.out.println(cs.toCompletableFuture().get());
        Single<String> single = mpRestClient.normalSingle();
        single.subscribe((String s) -> {
            System.out.println(s);
        });
    }
}