spring-boot: First request with WebClient slower in Spring Boot 2.4.0 compared to Spring Boot 2.3.6.RELEASE

Make a project with the dependency spring-boot-starter-webflux. Add the following simple test:

@SpringBootTest
class SlowWebClientTest {
    @Autowired
    WebClient.Builder builder;

    @Test
    void getRequest() {
        var client = builder.build();
        var body = client.get()
                .uri("https://reqres.in/api/users/1")
                .retrieve()
                .toBodilessEntity();
        StepVerifier.create(body).expectNextCount(1).verifyComplete();
    }
}

• With Spring Boot 2.4.0 it takes over 7.5 seconds to run this test.
• With Spring Boot 2.3.6.RELEASE it takes under 2.5 seconds to run this test.

I ran the test multiple times with both versions of Spring Boot.