AutoOpen for an infowindow atteched to a marker doesn't work

[Defcon0]

Hello,

I add an info window as on click event to some marker ike this:

$infoWindow = new InfoWindow($overlayConfig->infoWindowText);
                    $infoWindow->setPixelOffset(new Size($overlayConfig->infoWindowAnchorX, $overlayConfig->infoWindowAnchorY));
                    $infoWindow->setOpenEvent(MouseEvent::CLICK);
                    $infoWindow->setAutoOpen(true);

But the info window won't open automatically at all. Is it a bug or am I doing something wrong?