As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FT # 55, BOS-DCA. RETURNED TO FIELD. DOOR PAX AFT OPEN WARNING L2 THROUGH 6000 FT. PERFORMED QRM MESSAGE EXTINGUISHED AFTER PRESSURE DUMP BUTTON PRESSED ( DOOR POS IND ON MFD & ASSC EICAS-PAX (L1/L2) AND SERVICE (R1/R2) ); PERFORMED INSPECTION AND CHECK OF THE L2 DOOR AND SEAL. CABIN PRESSURIZATION NORMAL. AMM REF 21-31-01 AND 52-42-21. DOOR INDICATION PLACED ON MEL 52-70-00-A CAT C. MX-4 UPDATED, PLACARD INSTALLED. SUPPLEMENTAL INFORMATION TO FOLLOW. DEFECT OCCURED ON 2/29/2020