It's disgusting to see one of the views of the device manager expanded for hidden devices, because it means there must be something wrong with devices. If nothing is wrong, you see only the basic device views. Yesterday the view of the USB device was expanded showing some trouble. Even if I uninstalled the trouble device, it would soon appear as a failure. The connection to the motherboard was not good. So unplugged the terminals and reconnected them to it, and no lower level device would show themselves. What a relief.