As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SOUND OF AIR ESCAPING FROM UNKNOWN SOURCE IN PROXIMITY OF SEATS 19 - 22 ON RIGHT SIDE OF ACFT. FOUND A NOTICEABLE LEAK. LEAK FOUND APPROXIMATELY BS 952 WL 188. FOUND FUSELAGE DRAIN PLUNGER NEAR SEAT 20 STUCK IN OPEN POSITION. REMOVED DEBRIS FROM PLUNGER AND REINSTALLED. PERFORMED 8 PRESSURIZATION CYCLES OPS CHECKED GOOD.