wasm apps only receive the first mouse click

I can reproduce this on ubuntu 20.04. Cannot reproduce on windows.

Steps to reproduce:
1. Create a new app via qt creator.

2. Replace main.qml with this:

import QtQuick
Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")
    Rectangle {
        width: 300
        height: 300
        color: "green"
        MouseArea {
            anchors.fill: parent
            onClicked: console.log("clicked")
        }
    }
}

3. Build and run wasm single threaded. View the console output on the browser.

4. Click in the green area. You will see "clicked" appear in the console output.

5. Click again in the green area. There is no console output.

6. Move the mouse outside of the green area. You will see a message like this:
"Uncaught RuntimeError: index out of bounds
    qtStdWebEventCallbackActivate http://localhost:30001/qtloader.js line 461 > eval line 5891 > Function:8"

7. Move the mouse back inside the green area. Click. You will see "clicked" appear in the console output.