Ciao,
I was one of the 1st in the world to take delivery of the 339, so i can safely say that iv had mine longer than most have had theirs, and knowing me and what i do with my Panerai watches, added to the fact that i live in hot humid Asia plus i also sweat a fair bit, and yet my 339 sees NOTHING even close to the problems that occurs with this Risti's example.
I hope that OP gets to the bottom of this when he sents his piece in, and resolve the problem appropriately.
I must say though that Panerai Composite is one of the most elusive and mysterious materials used in modern watchmaking. Am yet to get to the REAL bottom of this enigma!
Ciao
Stephen