Ferrari 360 F1 noise

Any one else have this issue I started getting a loud slap noise when down gearing from 3 to 2nd like hitting a pice of thin medal
Had a the fluids changed but still have it Clutch is good with 70% left
Only seem to happen when the car as been driven for 20 or more minutes or warmed up
Everything else works fine shifts smoothly
Thanks for any help,