QML Button clicked event does not fire every time in WebAssembly

I build a Qt application for the web using WebAssembly. I noticed that clicked events of QML buttons are not received every time. However, if I move the mouse between clicks, every event is is received. Here is a minimal example:

import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.15

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")

    Button {
        onClicked: console.log("clicked")
    }
}

When I compile this to a WebAssembly application and run it in the browser, I can see the debug output of the onClicked handler only every second time I click the button.