As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRESSURIZATION FLUCTUATES AT LOWER ALTITUDES DURING CLIMB OR DECENT. FOUND OUT THROUGH TECHNICAL OPERATIONS THAT CONTROLLERS IN THE S/N RANGE OF 5000 THAT DID NOT HAVE MOD. LEVEL M EXPERIENCE THIS ISSUE. REPLACED WITH S/N 1124. ISSUE RESOLVED. BASE ON A LETTER RECEIVED, MANUFACTURER IS AWARE OF THIS ISSUE AND IS WORKING ON A RESOLUTION TO THE PROBLEM.