As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5359 - ON CLIMBOUT FROM LEX, RECEIVED PAX DOOR WARNING MESSAGE, MESSAGE WENT OUT 15-20 SECONDS LATER. RAN QRH AND AIRCRAFT RETURNED BACK TO LEX AND LANDED SAFELY. PERFORMED OPS CHECK OF PAX DOOR WARNING SYSTEM. OPS CHECK GOOD AND NO DEFECTS FOUND.