As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAV A SMOKE WARNING WENT OFF FOR 5 SECONDS IN FLIGHT. PERFORMED SELF TEST OF SMOKE WARNING SYSTEM OF LAV A, PER A321 AMM 26-17. NO FAULT DETECTED. INSPECTED F/C LAV NO SMELL DETECTED. FIRE EXTINGUISHER BOTTLE STILL IN GREEN BAN. NO 30 DAY HISTORY. A/C OK FOR SERVICE.