Issue with AsyncHealthCheck in extension

Question

I have an issue getting an AsyncHealthCheck working;

@Readiness
@ApplicationScoped
public class CoreApiHealthCheck implements AsyncHealthCheck {
    
    @RestClient
    OqmCoreApiClientService oqmCoreApiClient;
    
    @Override
    public Uni<HealthCheckResponse> call() {
        
        //fails with "The current thread cannot be blocked: vert.x-eventloop-thread-0"
        HealthCheckResponseBuilder responseBuilder = HealthCheckResponse.named("OqmCoreApi");
        return this.oqmCoreApiClient.getApiServerHealth()
                   .map((ObjectNode coreApiHealth) -> {
                       ObjectNode returned = this.oqmCoreApiClient.getApiServerHealth().await().indefinitely();
                       String status = returned.get("status").asText();
                       
                       if(status.equalsIgnoreCase(HealthCheckResponse.Status.UP.name())){
                           responseBuilder.up();
                       } else {
                           responseBuilder.down();
                       }
                       return responseBuilder.build();
                   })
                   .onFailure().recoverWithItem(e -> {
                       return responseBuilder.down().withData("error", e.getMessage()).build();
                   })
            ;
        
    }
}

This is the healthcheck I provide in my extension. The call this.oqmCoreApiClient.getApiServerHealth() returns a Uni, as I am using quarkus-rest-client-reactive. In my extension's test, I perform a simple healthcheck call:

public class CoreApiLibHealthCheckTest {
    
    @RegisterExtension
    static final QuarkusUnitTest config = new QuarkusUnitTest()
                                              .withEmptyApplication()
                                                  .overrideConfigKey("quarkus."+Constants.CONFIG_ROOT_NAME + ".health.enabled", "true");
    
    @Test
    public void testDataSourceHealthCheckExclusion() {
        ValidatableResponse response = RestAssured.when().get("/q/health")
            .then();
        
        System.out.println(response.extract().body().asPrettyString());
        
        response.statusCode(200)
            .body("status", CoreMatchers.equalTo("UP"));
    }
}

Which comes back with:

{
    "status": "DOWN",
    "checks": [
        {
            "name": "OqmCoreApi",
            "status": "DOWN",
            "data": {
                "error": "java.lang.IllegalStateException - The current thread cannot be blocked: vert.x-eventloop-thread-0"
            }
        }
    ]
}

It appears that the test server spun up has issues with reactive, what can I do to ensure it is using Reactive?