WASM: Quick Window is bigger than browser frame on mobile browsers

On mobile browsers wasm quick apps are cut off at the bottom.
It looks like the app sizes the window to the screensize of the device instead of the actual browser frame.

Result Firefox Desktop:

Result Chrome Desktop:

Result Firefox Android app:

Result Chrome Android app:

Example app:

import QtQuick 2.15
import QtQuick.Window 2.15

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")
    Rectangle{
        height: parent.height
        width: parent.width
        color: "blue"
        Rectangle{
            x: 50
            y: 50
            height: parent.height - 2 * x
            width: parent.width - 2 * y
            color: "white"
        }
    }
}

Slightly offtopic:
I tried getting Qt 6.1.2/6.2.0 Beta built from source for webassembly to check if it was an issue there, but I could not get the builds to work on windows. Should they work?

Slightly more offtopic:
I had to upload the images somewhere else and link to the images, I could not attach images or the example project.