TextInput not editable in browser

SyntaX

I just setup a minimalistic example project

import QtQuick 2.15
import QtQuick.Window 2.15

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Text Input Test")

    TextInput {
        text: "predefined Text"
    }
}

If I compile for desktop (macOS), the textInput works as intended: I am able to click into the element and change the text by typing on my hardware keyboard :D

But if I compile the same project for WebAssembly, the predefined text gets shown, I am able to click in the textInput (also the onFocusChanged event triggers) but I cannot edit the text?
For debugging I added onTextEdited and onTextChanged listeners, they both seem to don't get called?

Am I missing something important here or can this be related to this bug report:
https://bugreports.qt.io/browse/QTBUG-80449?page=com.atlassian.jira.plugin.system.issuetabpanels%3Achangehistory-tabpanel

Qt version 5.15 for clang and WebAssembly,
Emscripten version 1.39.17

SyntaX

I noticed, that although I am not able to "write" Text in the input field, I can paste text from elsewhere?