spring-cloud-gateway: When i use the getFormData in GlobalFilter produces error

When a use exchange.getFormData(), the spring cloud gateway produces java.lang.IllegalStateException: Only one connection receive subscriber allowed., anyone can help me?

Follow snippet (follow a simple example of what I’m trying to):

@Component
public class SampleFilter implements GlobalFilter, Ordered  {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        return exchange.getFormData()
                .flatMap(s -> chain.filter(exchange));
    }

    @Override
    public int getOrder() {
        return Ordered.LOWEST_PRECEDENCE;
    }
}

Stacktrace:

java.lang.IllegalStateException: Only one connection receive subscriber allowed.
	at reactor.ipc.netty.channel.FluxReceive.startReceiver(FluxReceive.java:276) ~[reactor-netty-0.7.8.RELEASE.jar:0.7.8.RELEASE]
	at reactor.ipc.netty.channel.FluxReceive.lambda$subscribe$2(FluxReceive.java:127) ~[reactor-netty-0.7.8.RELEASE.jar:0.7.8.RELEASE]
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) ~[netty-common-4.1.25.Final.jar:4.1.25.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404) ~[netty-common-4.1.25.Final.jar:4.1.25.Final]
	at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:313) ~[netty-transport-native-epoll-4.1.25.Final-linux-x86_64.jar:4.1.25.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884) ~[netty-common-4.1.25.Final.jar:4.1.25.Final]
	at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_181]

NOTES: spring cloud version: Finchley.RELEASE spring cloud gateway core version: 2.0.1.RELEASE

Thanks 😄