As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL370 NEAR COAST IN CABIN PRESSURE RATE OF CLIMB BEGAN TO VARY BETWEEN 1000FPM CLIMB AND 500FPM DESENT. AFTER TWO MINUTES CABIN STABILIZED AT 8000 AND RATE SETTLED. PERFORMED GROUND TEST BITE PROCEDURE ON NR 1&2 DIGITAL CABIN PRESSURE CONTROLLER AND SYSTEM TEST OK REF FIM TASK 21 31 00 810 801 AND NO 30 DAY HISTORY NOTED A/C OK FOR SERVICE.