Actix channel issue

Cargo.toml

[package]
name = "test"
version = "0.1.0"
edition = "2018"

[dependencies]
actix-web = "4.0.0-beta.4"
tokio = { version = "1", features = ["full"] }

main.rs

use actix_web::{web, App, HttpResponse, HttpServer, Responder};
use tokio::sync::broadcast::{self, Sender};

async fn send(tx: web::Data<Sender<String>>, data: String) -> Result<HttpResponse, HttpResponse> {
    println!("Sender count: {}", tx.receiver_count());
    tx.send(data).map_err(|err| {
        println!("Could not send to channel. {:?}", err);
        HttpResponse::InternalServerError()
    })?;
    println!("Sent data");

    Ok(HttpResponse::Ok().body("ok"))
}

async fn receive(tx: web::Data<Sender<String>>) -> impl Responder {
    let mut rx = tx.subscribe();
    tokio::spawn(async move {
        println!("Spawned listener...");
        while let Ok(data) = rx.recv().await {
            println!("Received data: {:?}", data);
        }
        println!("Exited listener...");
    });

    HttpResponse::Ok().body("ok")
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        let (tx, _rx) = broadcast::channel::<String>(10);

        App::new()
            .data(tx)
            .route("/send", web::post().to(send))
            .route("/receive", web::get().to(receive))
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await
}

// 1. SPAWN RECEIVER
// $ curl http://localhost:8080/receive

// 2. SEND MESSAGE
// $ curl http://localhost:8080/send --data hello