select with multiple tokio::sync::mpsc receivers silently drops messages

[Zdbldds]

I have a service that receives commands on one channel and events on another. I'm using tokio::select! to listen on both simultaneously, but when messages arrive quickly on both channels, some get lost. I checked the buffer sizes and they're not full.
Version: tokio 1.41.1, rustc 1.82.0

use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (cmd_tx, mut cmd_rx) = mpsc::channel::<String>(100);
    let (evt_tx, mut evt_rx) = mpsc::channel::<String>(100);

    let cmd_tx_clone = cmd_tx.clone();
    tokio::spawn(async move {
        for i in 0..50 {
            cmd_tx_clone.send(format!("cmd-{i}")).await.unwrap();
        }
    });

    tokio::spawn(async move {
        for i in 0..50 {
            evt_tx.send(format!("evt-{i}")).await.unwrap();
        }
    });

    let mut cmd_count = 0u32;
    let mut evt_count = 0u32;
    let mut cmd_done = false;
    let mut evt_done = false;

    while !cmd_done || !evt_done {
        tokio::select! {
            msg = cmd_rx.recv(), if !cmd_done => {
                match msg {
                    Some(_cmd) => {
                        cmd_count += 1;
                    }
                    None => cmd_done = true,
                }
            }
            msg = evt_rx.recv(), if !evt_done => {
                match msg {
                    Some(_evt) => {
                        evt_count += 1;
                    }
                    None => evt_done = true,
                }
            }
        }
    }

    println!("cmds: {cmd_count}, evts: {evt_count}");
    // Now always: cmds: 50, evts: 50
}

Every run gives me different numbers for evt_count, always less than 50. The send() calls never fail, so the messages are definitely being sent. I can't figure out where they're being lost.
Any ideas? Thanks in advance.

[Darksonn]

The program you shared runs forever. Please share the correct example.

[felipeinf]

was about to say the same thing

[Zdbldds]

I think I got it, thks

[felipeinf]

The original cmd_tx is never dropped (it lives until the end of main), so cmd_rx.recv() never returns None, cmd_done never becomes true, and the loop never exits.
But apparently that wasnt your problem