SpinBox resets to "from" value when loses focus

Button {
    id:but1
}
SpinBox {
    focus: true
    KeyNavigation.backtab: but1
    KeyNavigation.tab: but2
    KeyNavigation.left: but1
    KeyNavigation.right: but2
    from: 10
    to: 1000
    value: 100
    onValueChanged: but1.text = "aa " + value
}
Button {
    id:but2
}

Steps to reproduce:

• change the sinbox value
• press tab|backtab|left|right hey
  Spingbox will reset the value to 10 ("from" value).
• same thing happens if you just press on any button

:/qtlabscontrols.conf
[Controls]
Style=Material

[Material]
Theme=Dark
Accent=Teal
Primary=BlueGrey