Check whether the gloss enhancer head side takes grey ink in from its other half and uses that in that first inch of printing. There have been more reports like that. Either a leak in the barrier between the head parts or the grey ink is getting in at the parking station or whatever it is called. Probably the first.
Print an image without gloss enhancer and print gloss enhancer without an image (smaller image on a larger print page and GE all over).
met vriendelijke groeten, Ernst