Vert.x event bus consumer called twitce - vert.x

Question

i wrote a simple code for communicate between a java server in vert.x and a browser client with the event bus library. The client send a message to the server through the event bus and the server call eventbus.consumer to read the message and reply to it.
I notice something strange, idk why the consumer method is called twice, I aspect it call one. How can i solve this? Thanks.
This is my code:
SERVER
SockJSBridgeOptions options = new SockJSBridgeOptions().
addInboundPermitted(new PermittedOptions().setAddressRegex("out"));
sockJSHandler.bridge(options);
router.route("/eventbus/*").handler(sockJSHandler);
eventBus.<String>consumer("out", event -> {
logger.info(event.body());
event.reply("TEST");
});
vertx.createHttpServer().requestHandler(router).listen(serverPort, res -> {
if (res.succeeded()) {
startPromise.complete();
} else {
startPromise.fail(res.cause());
}
});
CLIENT
var eb = new EventBus('http://localhost:8088/eventbus');
eb.onopen = () => {
eb.send('out', {name: 'tim', age: 5817}, (e, m) => {
console.log("TEST RESPONSE")
console.log(JSON.stringify(m));
});
}
CONSOLE SERVER OUTPUT
apr 07, 2022 7:55:43 PM it.unibo.guessthesong.lobby.LobbyVerticle
INFO: {"name":"tim","age":5817}
apr 07, 2022 7:55:43 PM it.unibo.guessthesong.lobby.LobbyVerticle
INFO: {"name":"tim","age":5817}
CONSOLE CLIENT OUTPUT
TEST RESPONSE
{"type":"rec","address":"92888ada-fada-43ff-9677-9eeed95b44da","body":"TEST"}
TEST RESPONSE
{"type":"rec","address":"2ced1214-13cf-4ebf-b7d8-6773612097e7","body":"TEST"}