Qt 5.15 "Unhandled key code" on Android (PAX A920)

[Fausto01]

I have an empty Qt Quick app that runs on Android on a PAX A920 device.
My main.qml is this:

import QtQuick 2.12
import QtQuick.Window 2.12

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

    Item {
        anchors.fill: parent
        focus: true
        Keys.onReleased: { console.log("KEY RELEASED " + event.key + " " + event.modifiers + " " + event.nativeScanCode); event.accepted = true }
    }
}

When I press the Android home button, nothing happens, and the console is printing this error:

W libAndroidTest_armeabi-v7a.so: Unhandled key code  3 !
D libAndroidTest_armeabi-v7a.so: qml: KEY RELEASED 0 0 0

The same thing is happening when I press the square button for listing opened apps:

W libAndroidTest_armeabi-v7a.so: Unhandled key code  187 !
D libAndroidTest_armeabi-v7a.so: qml: KEY RELEASED 0 0 0

On my phone everything works, so it seems related to PAX A920, but WhatsApp installed on the PAX works good.
How can I solve this problem? I don't need to intercept the home button in my app, I just need it to work.
I made an empty project with Android Studio and the navbar works correctly. Unfortunately I need to make it work with Qt.