OK figured it out.
Here are the instructions:-
1)
Fully open the door and then loosen (but do not remove) this bolt (M8 spline)
2) Now
half close the door (2 detents on the lower hinge), drop the window and get a firm hold of the window frame by the corner. Whilst firmly lifting the door the full arc,
fully open it again. It's important you maintain the firm lift whilst opening, otherwise it won't adjust. Nip up the M8 bolt and check the alignment. Rinse and repeat.
The objective is to get this nub to turn more to the right which lifts the door, and when it moves to the left, it lowers the door. Factory default position is as pictured. Mine needed moving round a good few mm.