failed to resolve. GET HEALTH

org.springframework.web.reactive.function.client.WebClientRequestException: failed to resolve 'DESKTOP-ML2NQ33' after 9 queries ; nested exception is java.net.UnknownHostException: failed to resolve 'DESKTOP-ML2NQ33' after 9 queries 
    at org.springframework.web.reactive.function.client.ExchangeFunctions$DefaultExchangeFunction.lambda$wrapException$9(ExchangeFunctions.java:137) ~[spring-webflux-5.3.3.jar:5.3.3]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ Request to GET health [DefaultWebClient]
Stack trace:

2021-02-18 14:43:03.356 ERROR 1288 --- [nio-8081-exec-3] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.reactive.function.client.WebClientRequestException: failed to resolve 'DESKTOP-ML2NQ33' after 9 queries ; nested exception is java.net.UnknownHostException: failed to resolve 'DESKTOP-ML2NQ33' after 9 queries ] with root cause

alguém sabe por que estou tendo este erro?

//Configurações de Autorização
    @Override
    protected void configure(HttpSecurity http) throws Exception {

        http.authorizeRequests()
        .antMatchers(HttpMethod.GET,"/topicos").permitAll()
        .antMatchers(HttpMethod.GET,"/topicos/*").permitAll()
        .antMatchers(HttpMethod.POST,"/auth").permitAll()
        .antMatchers(HttpMethod.GET,"/actuator/**").permitAll()    
        .anyRequest().authenticated()
        //.and().formLogin(); para não criar sessão pois não estamos utilizando token e cookie.        
        .and().csrf().disable()
        .sessionManagement()
        .sessionCreationPolicy(SessionCreationPolicy.STATELESS)
        .and().addFilterBefore(new AutenticacaoViaTokenFilter(tokenService, usuarioRepository), UsernamePasswordAuthenticationFilter.class);

    }

application,properties do forum

#actuator

management.endpoint.health.show-details=always
management.endpoint.web.exposure.include=*
info.app.name=@project.name@

spring.boot.admin.client.url=http://localhost:8081

application.properties do boot admin

server.port=8081

O boot admin até indentifica a instância, mas a mesma aparece como DOWN.