As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: SMOKE LAVATORY SMOKE WARNING FOR APPROXIMATELY 3 SECONDS. NO SMOKE FOUND IN ANY LAVATORY, BUT SUSPECTED PASSENGER IN FIRST CLASS LAVATORY OF VAPING. MAINTENANCE PERFORMED BITE CHECKS OF SMOKE DETECTOR CONTROL UNIT PER AMM 26-17-00, NO DEFECTS NOTED.