As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT LOST PRESSURIZATION AT 17,000 FEET. SLOW LOSS OF PRESSURIZATION, DESCENDED PER QRH. RETURNED TO LAX. INSPECTED AND FOUND SMALL SECTION OF CARGO DOOR SEAL LOOSE FROM RETAINER. REINSTALLED AND SECURED CARGO DOOR SEAL. PRESSURIZED AIRCRAFT TO 5+ PSID. NO LEAKS NOTED. PRESSURIZATION OPS CHECKS GOOD.