As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A NOISE WAS HEARD FROM AROUND THE R-3 DOOR AFTER LANDING AT IAH. MAINTENANCE FOUND THE AFT CARGO DOOR OPERATIONAL SWITCH WAS STICKING INTERMITTENTLY IN THE CLOSED POSITION CAUSING THE DOOR TO CONTINUE TO CLOSE AFTER THE SWITCH WAS RELEASED. THE CARGO DOOR SWITCH WAS REMOVED AND REPLACED AND OPERATIONAL CHECKS WERE GOOD.