As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ATTENDANTS REPORTED PRESSURIZATION SQUEAL IN AFT GALLEY AREA. NOISE DID NOT INTERFERE WITH COMMUNICATION. GROUNDED - YES. ACCOMPLISHED EA-900ER-21EA-25149 CREATED DEFERRAL ON L/P 60365461 TO REPLACE EXISTING OUTFLOW VALVE WITH A P/N 21230-(*) VALVE WITHIN 150 FLIGHT HOURS OF 01/11/23.