I too have the same problem with my Multi, the paint has flaked off in various places and corrosion (white powdery deposits) are widespread.
I think that this is due to expansion and contraction (engine getting hot and cold) this leaves a void between the paint and engine thus enabling the paint to crack and flake off and allowing water and salt to penetrate and corrode the aluminium.
It also appears that not only is the paint a thin coat, I don't think Ducati used a primer
this is particularly important with aluminium because an
etching primer is required prior to a top or finishing coat.
As I am the second owner unfortunately I do not have recourse with Ducati or a dealer.
I shall approach somebody who can paint the engine properly, after all as with most other jobs 95% of the work is in the preparation.
If anyone receives any quotes to carry out remedial work I would be very interested to know.