TemplateSelector in CollectionView is not firing if the Device is rotated

I am using Template Selectors in ListViews successfully, where I detect if the Device is in landscape or portrait mode. When I rotate my devices the Class refreshes the Templates and I can change my Layout on the fly. Perfect !
Recently I use CollectionView and want to use the same technique, but the TemplateSelector is not updated when I rotate the device. Is this a mistake or do I have to pay attention to something here ?