Freeze when tab button is pressed after clicked button goes invisible

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Controls 2.3
import QtQuick.Controls.Material 2.12

Window {
    property bool buttons_are_visible: true

    Timer {
        interval: 2000
        running: true
        repeat: false
        onTriggered: buttons_are_visible = false
    }

    Button {
        text: "Click"
        visible: buttons_are_visible
    }
}