Parent not receiving message

[finchi]

Hey, I'm not able to receive message on my parent

parent.html

<iframe id="content" src="child.html"></iframe>

parent.js

import 'seamless/build/seamless.parent'

$(document).ready(() => {
    let child = $("iframe#content").seamless();
    child.receive(function(data, event) {
        // Print out the data that was received.
        console.log(data);
    });
});

child.js

import 'seamless/build/seamless.child'

let parent = window.seamless.connect();

// Send a message
parent.send({
    myparam: 'This is anything you want it to be...'
});

The problem, as far as I can see, is that on the parent.receive the check if (data.__id && (data.__id === _self.id)) fails, because the data.__id is 0. Looks like the child doesn't get the parents ID on connect.

Any idea what I did wrong?