“PrivateActionToolButton_QMLTYPE_XX(0x00000000)” is the type and address of the actively focused item and “Sort” is the accessible name of this item. If this is the case, ensure that your control has a text property set even if the control itself overrides the contentItem or is an icon only button. There is an helpful property in QQC2.Control named visualFocus which should be true when the user uses keyboard navigation to focus on a specific item.