On Android TV with a remote, the system keyboard and the input field behave erratically and are not in sync, corrupting input. Using the following:

Window {
    width: 640
    height: 480
    visible: true

    Column {
        width: 400
        anchors.centerIn: parent

        TextInput {
            id: input
            height: 40
            width: 300
            text: "Input field"
            color: "black"
            focus: true
        }

        Text {
            text: "Value: " + input.text
            font.bold: true
        }
    }
}

On all other platforms, including mobile with a pop-up keyboard, this responds as expected and the matching output field stays in sync.  However on TVs, if you simply key in an 'x', then the input is corrupted with a copy of some of it's existing text appended.   If you start hitting backspace, you can erase the 'extra' content and eventually it will again append some of the remaining text.  Basically it's very broken.

Also, on all other platforms the display field matches the input field per-keystroke.  The  TV system keyboard events aren't processed per keystroke, and you don't know what you'll get until you finish. 

Tested on Google TV Android 10 & 11.  FireOS has a variant of this issue as well.  Qt 6.6.3 also has this issue though with slightly different behavior.