Hi Juani,
What I can tell you is I use have the Hepco Becker easy rack basically same as Alurack, same support mounting system.
After 9000 miles my Grab Rail has cracked. I noticed when cleaning the bike the arms that support the the rack that holds top case had cracked on both sides. When I removed the mounting system I discovered that this also created a crack in grab rail right under the rubber gourmet on the center of the grab rail. The grab rail part is all one piece that is the whole box under the pillion seat.
$489.00 USD from Ducati does not include installation and looks like the power outlets would need to be disconnected to replace the part.
You should check under your mount.