A bit late to this party, sorry :oops:
You need to check the freehub is tight (remove non-drive side cap, 10mm Allen key in making sure it’s seated correctly – 5mm Allen key in drive side then try and tighten). If that doesn’t sort out the play then it’s new freehub time.
I doubt it’s Campag to blame, Italian it may be but boy does it work.
[edit] Should have said, I may not have 10 years experience wrenching in a bike shop but I do have the hands of the most cack-handed person you’re ever likely to meet, if I can get it to work faultlessly, without any faff then it’s Campag all the time for me (once indexed, that I manage to do first time, then it never needs adjusting until I replace the cables yearly).