As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKE OFF ROLL AT 30 KNOTS SERVICE DOOR WARNING APPEARED. VERIFIED SERVICE DOOR CLOSED AND LATCHED. C/W FLT CREW PROCEDURE. 00 FACT 09MAY21 00:33 MDT. INSPECTED SERVICE DOOR AND RAN TEST IRT AMM 52-74-00 CND DISCREPANCY. OPS CHECK GOOD AND OK FOR RETURN TO SERVICE AT THIS TIME.