As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#1379, DCA-FLL. (AIRCRAFT PERFORMED AN AIR TURN BACK TO FLL). 'AFT CARGO DOOR CAUTION MESSAGE DISPLAYED AFTER TAKEOFF( ECAM IND CARGO DOOR (FWD/AFT & BULK) ); REMOVED AND REPLACED AFT CARGO DOOR PROXIMITY SENSOR FIN # 32WV IAW AMM 52-71-12. OPS CHECK OK. INDICATION NORMAL. THIS CLEARS MDDR # 471494. MX-4 UPDATED. MCC NOTIFIED. PLACARD REMOVED.'