As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN ALTITUDE WARNING CLIMBING THROUGH FL 225. AIR TURN BACK SECURED LOOSE DUCT AND LOOSE SUPPORT RODS AT RH PACK PLENUM MAIN DUCT. REF IPC 21-51-15-01 ITEM 215 AND 203. WILL REQUIRE ACFT PRESSURIZATION CHECK WITH BOTH PACK OPERATING.